Flux through a closed surface of any shape and flux
through the surface of a sphere drawn around a charge are:
Many people like to eat pizza, but
not everyone knows knows how to make it. Making the perfect pizza can be complicated,
but there are lots of ways for you to make basic version at home.
When you make pizza, you must
begin with the crust. The crust can be hard to make. If you want to make the
crust yourself, you will have to make dough using flour, water, and yeast. You
will have to knead the dough with your hands. If you do not have enough time to
do this, you can use a prepared crust that you buy from the store.
After you have chosen your crust,
you must then add the sauce. Making your own sauce from scratch can take a long
time. You have to buy tomatoes, peel them, and then cook them with spices. If
this sounds like too much work, you can also purchase jarred sauce from the
store. Many jarred sauces taste almost as good as the kind you make at home.
Now that you have your crust and
your sauce, you need to add the cheese. Cheese comes from milk, which comes
from cows. Do you have a cow in your backyard? Do you how to milk the cow? Do
you know how to turn that milk into cheese? If not, you might want to buy
cheese from the grocery store instead of making it yourself. When you have the
crust, sauce, and cheese ready, you can add other toppings. Some people like to
put meat on their pizza, while other people like to add vegetables. Some people
even like to add pineapple! The best part of making a pizza at home is that you
can customize it by adding your own favorite ingredients
In paragraph 3, the author writes,
“Many jarred sauce taste almost as good as the kind you make at home.” The
purpose of this statement is to
First introduced in 1927, The Hardy
Boys Mystery Stories are a series of books about the adventures of brothers
Frank and Joe Hardy, teenaged detectives who solve one baffling mystery after
another. The Hardy Boys were so popular among young boys that in 1930 a similar
series was created for girls featuring a sixteen-year-old detective named Nancy
Drew. The cover of each volume of The Hardy Boys states that he author of the
series is Franklin W. Dixon; the Nancy Drew Mystery Stories are supposedly
written by Carolyn Keene. Over the years, though, many fans of both series have
been surprised to find out that Franklin W. Dixon and Carolyn Keene are not
real people. If Franklin W. Dixon and Carolyn Keene never existed, then who
wrote The Hardy Boys and Nancy Drew mysteries?
The Hardy Boys and the Nancy Drew
books were written through a process called ghostwriting. A ghostwriter writes
a book according to a specific formula. While ghostwriters are paid for writing
the books, their authorship is not acknowledged, and their names do not appear
on the published books. Ghostwriters can write books for children or adults,
the content of which is unspecific. Sometimes they work on book series with a
lot of individual titles, such as The Hardy Boys and the Nancy Drew series.
The initial idea for both The Hardy
Boys and the Nancy Drew series was developed by a man named Edward Stratemeyer,
who owned a publishing company that specialized in children’s book.
Stratemeyer noticed the increasing
popularity of mysteries among adult, and surmised that children would enjoy
reading mysteries about younger detectives with whom they could identify.
Stratemeyer first developed each book with an outline describing the plot and
setting. Once he completed the outline, Stratemeyer then hired a ghostwriter to
convert it into a book of slightly over 200 pages. After the ghostwriter had
written a draft of a book, he or she would send it back to Stratemeyer, who
would make a list of corrections and mail it back to the ghostwriter. The
ghostwriter would revise the book according to Stratemeyer’s instructions and
then return it to him. Once Stratemeyer approved the book, it was ready for
publication.
Because each series ran for so many
years, Nancy Drew and The Hardy Boys both had a number of different
ghostwriters producing books; however, the first ghostwrites for each series proved
to be the most influential. The initial ghostwriter for The Hardy Boys was a
Canadian journalist named Leslie McFarlane. A few years later, Mildred A. Wirt,
a young writer from lowa, began writing the Nancy Drew books. Although they
were using prepared outlines as guides, both McFarlane and Wirt developed the
characters themselves. The personalities of Frank and Joe Hardy and Nancy arose
directly from McFarlane’s and wirt’s imaginations. For example, Mildred Wirt
had been a star college athelete and gave Nancy similar athletic abilities. The
ghostwriters were also responsible for numerous plot and setting details.
Leslie McFarlane used elements of his small C fictional hometown.
Although The Hardy Boys and Nancy
Drew books were very popular with children, not everyone approved of them.
Critics thought their plots were unrealistic and even far-fetched, since most
teenagers did not experience the adventures Frank and Joe Hardy or Nancy Drew
did. The way the books were written also attracted criticism. Many teachers and
librarians objected to the ghostwriting process, claiming it was designed to
produce books quickly rather than create quality literature. Some libraries –
including the New York Public Library – even refused to include the books in
their children’s collections. Ironically, this decision actually helped sales
of his books, because children simply purchased them when they were unavailable
in local libraries.
Regardless of the debates about
their literary merit, each series of books has exerted an undeniable influence
on American and even global culture. Most Americans have never heard of Edward
Stratemeyer, Leslie McFarlane, or Mildred wirt, but people throughout the world
are familiar with Nancy Drew and Frank and Joe Hardy.
Which of the following best
describes the structure of this passage?
The history of the modern world is a
record of highly varied activity, of incessant change, and of astonishing
achievement. The lives of men have, during the last few centuries, increasingly
diversified, their powers have greatly multiplied, their powers have greatly
multiplied, their horizon been enormously enlarged. New interests have arisen
in rich profusion to absorb attention and to provoke exertion. New aspirations
and new emotions have come to move the soul of men. Amid all the bewildering phenomena,
interest, in particular, has stood out in clear and growing pre-eminence, has expressed
itself in a multitude of ways and with an emphasis more and more pronounced,
namely, the determination of the race to gain a larger measure of freedom than
it has ever known before, freedom in the life of the intellect and spirit,
freedom in the realm of government and law, freedom in the sphere of economic
and social relationship. A passion that has prevailed so widely, that has transformed
the world so greatly, and is still transforming it, is one that surely merits
study and abundantly rewards it, its operations constitute the very pith and
marrow of modem history.
Not that this passion was unknown to
the long ages that proceeded the modern periods. The ancient Hebrews, the
ancient Greeks and Roman blazed the was leaving behind them a precious heritage
of accomplishments and suggestions and the men who were responsible for the
Renaissance of the fifteenth century and the Reformation of the sixteen century
contributed their imperishable part to this slow and difficult emancipation of
the human race. But it is in modern times the pace and vigour, the scope and
sweep of this liberal movement have so increased unquestionably as to dominate
the age, particularly the last three centuries that have registered great
triumphs of spirit.
In what period of the history of the
world have the lives of men become increasingly diversified?
When her grandmother’s health began to deteriorate in the
fall of 1994, Mary would make the drive from Washington, DC to Winchester every
few days.
She hated highway driving, finding it ugly and monotonous. She
preferred to take meandering back roads to her grandmother’s hospital. When she
drove through the rocky town of Harpers Ferry, the beauty of the rough waters
churning at the intersection of the Shenandoah and Potomac rivers always
captivated her.
Toward the end of her journey, Mary had to get on highway
81. It was here that she discovered a surprising bit of beauty during one of
her trips. Along the median of the highway, there was a long stretch of
wildflowers. They were thin and delicate and purple, and swayed in the wind as
if whispering poems to each other.
The first time she saw the flowers, Mary was seized by an uncontrollable
urge to pull over on the highway and yank a bunch from the soil. She carried
them into her grandmother’s room when she arrived at the hospital and placed
them in a water pitcher by her bed. For a moment her grandmother seemed more
lucid than usual. She thanked Mary for the flowers, commented on their beauty
and asked where she had gotten them. Mary was overjoyed by the ability of the
flowers to wake something up inside her ailing grandmother.
Afterwards, Mary began carrying scissors in the car during
her trips to visit her grandmother. She would quickly glide onto the shoulder,
jump out of the car, and clip a bunch of flowers. Each time Mary placed the
flowers in the pitcher, her grandmother’s eyes would light up and they would
have a splendid conversation.
One morning in late October, Mary got a call that her
grandmother had taken a turn for the worse. Mary was in such a hurry to get to
her grandmother that she sped past her flower spot. She decided to turn around
head several miles back, and cut a bunch. Mary arrived at the hospital to find her
grandmother very weak and unresponsive. She placed flowers in the pitcher and
sat down. She felt a squeeze on her fingers. It was the last conversation they
had.
What other title would best fit this passage?
It is easy to make delicious-looking hamburger at home. But would this
hamburger still look delicious after it sat on your kitchen table under very
bright lights for six or seven hours? if someone took a picture or made a video
of this hamburger after the seventh hour, would anyone want to eat it? More
importantly, do you think you could get millions of people to pay money for
this hamburger? These are the questions that fast food companies worry about
when they produce commercials or print ads for their products. Video and photo
shoots often last many hours. The lights that the photographers use can be
extremely hot. These conditions can cause the food to look quite unappealing to
potential consumers. Because of this, the menu items that you see in fast food
commercials are probably not actually edible.Let's use the hamburger as an
example. The first step towards building the commercial hamburger is the bun.
The food stylist--a person employed by the company to make sure the products
look perfect--sorts through hundreds of buns until he or she finds one with no
wrinkles. Next, the stylist carefully rearranges the sesame seeds on the bun
using glue and tweezers for maximum visual appeal. The bun is then sprayed with
a waterproofing solution so that it will no get soggy from contact with other
ingredients, the lights, or the humidity in the room.Next, the food stylist
shapes a meat patty into a perfect circle. Only the outside of the meat gets
cooked-the inside is left raw so that the meat remains moist. The food stylist
then paints the outside of the meat patty with a mixture of oil, molasses, and
brown food coloring. Grill marks are either painted on or seared into the meat
using hot metal skewers.Finally, the food stylist searches through dozens of
tomatoes and heads of lettuce to find the best-looking produce.One leaf of the
crispest lettuce and one center slice of the reddest tomato are selected and
then sprayed with glycerin to keep them looking fresh. So the next time you see
a delectable hamburger in a fast food commercial, remember: you are actually
looking at glue, paint, raw meat , and glycerin. Are you still hungry?
Question:
Based on information in the passage, it is most important for the lettuce and tomato used in a fast food hamburger commercial to
The year 2006 was the golden
anniversary, or the 50th birthday, of the Dwight D. Eisenhower
National System of Interstate and Defense Highways. This system, usually
referred to as The Interstate Highway System, is a system of freeways named
after the U.S. President who supported it. The system is the largest highway
system in the world, consisting of 46,876 miles (75,440 km) of freeways. The
construction of the interstate highway system is an important part of American
history. It has played a major role in preserving and maintaining the America way of life.
The interstate highway system has
several major functions. One of its major functions is to facilitate the distribution of US good. Because the
intestate passes through many downtown areas, it plays an important role in the
distribution of almost all goods in the United States.
Nearly all products travel at least part of the way to their destination on the
Interstate System. Another major function of the interstate is to facilitate
military troop movement to and from airports, seaports, rail terminals and
other military destinations. The Interstate highways are connected to route in
the Strategic Highway Network, which is a system of highways that are vital to the U.S. Department of Defense.
Today, most of the Interstate system
consists of newly constructed highways. The longest section of the Interstate
system runs from Boston, Massachusetts to Seattle, Washington. It covers
3,020.54 miles. The shortest two-digit interstate is from Emery, North Caroline
to Greensboro, North Caroline. It covers only 12.27 miles. All state capitals
except five are served by the system. The five that are not directly served are
Juneau, AK, Dover, DE, Jefferson City, MO, Carson City, NV, and Pierre, SD. The
Interstate Highway System serves almost all major U.S. cities.
EACH Interstate highway is marked
with a red, white, and blue shield with the word “Interstate,” the name of the
state, and the route number. Interstate highways are named with one or
two-digit numbers. North-south highways are designated with odd numbers; east-west highways are
named with even numbers. The north-south Interstate highways begin in the west
with the lowest odd number; the east-west highways begin in the south with the
lowest even numbers. There all mile markers at each mile of the interstate
system, starting at the westernmost or southernmost point on the highway. Every
Interstate highway begins with the number “0”. Interchanges are numbered
according to their location on the highway in relation to mileage; an exit
between milepost 7 and milepost 8 would be designated “Exit 7.” This system
allows drivers estimate the distance to a desired exit, which a road is leading
off the highway. Despite the common acceptance of the numbering system on the
Interstate highways, some states have adopted different numbering systems. For
example, a portion of the Interstate 19 in Arizona is measured in kilometers
instead of miles since the highway goes south to Mexico.
Since the Interstate highways are
freeways-highways that do not have signs and cross streets – they have the
highest speed limits in the nation. Most interstate highways have speed limits
between 65 – 75 miles per hour (105 – 120 kilometers per hour), but some areas
in Texas and Utah have an 80 mile-per-hour (130 kilometer-per-hour) speed
limit.
The federal government primarily
funds interstate highways. However, they are owned and operated by the
individual states or toll authorities in the states. The federal government
generally funds up to 90% of the cost of an Interstate highway, while the
states pay the remainder of the cost.
When you facilitate something, you
It is easy to make delicious-looking hamburger at home. But would this
hamburger still look delicious after it sat on your kitchen table under very
bright lights for six or seven hours? if someone took a picture or made a video
of this hamburger after the seventh hour, would anyone want to eat it? More
importantly, do you think you could get millions of people to pay money for
this hamburger? These are the questions that fast food companies worry about
when they produce commercials or print ads for their products. Video and photo
shoots often last many hours. The lights that the photographers use can be
extremely hot. These conditions can cause the food to look quite unappealing to
potential consumers. Because of this, the menu items that you see in fast food
commercials are probably not actually edible.Let's use the hamburger as an
example. The first step towards building the commercial hamburger is the bun.
The food stylist--a person employed by the company to make sure the products
look perfect--sorts through hundreds of buns until he or she finds one with no
wrinkles. Next, the stylist carefully rearranges the sesame seeds on the bun
using glue and tweezers for maximum visual appeal. The bun is then sprayed with
a waterproofing solution so that it will no get soggy from contact with other
ingredients, the lights, or the humidity in the room.Next, the food stylist
shapes a meat patty into a perfect circle. Only the outside of the meat gets
cooked-the inside is left raw so that the meat remains moist. The food stylist
then paints the outside of the meat patty with a mixture of oil, molasses, and
brown food coloring. Grill marks are either painted on or seared into the meat
using hot metal skewers.Finally, the food stylist searches through dozens of
tomatoes and heads of lettuce to find the best-looking produce.One leaf of the
crispest lettuce and one center slice of the reddest tomato are selected and
then sprayed with glycerin to keep them looking fresh. So the next time you see
a delectable hamburger in a fast food commercial, remember: you are actually
looking at glue, paint, raw meat , and glycerin. Are you still hungry?
Question:
Something is edible of it
Right now, I am looking at a shelf
full or relics, a collection of has-beens, old-timers, antiques, fossils. Right
now I am lolling at a shelf full of books. Yes that’s right. If you have some
spare cash (the doing rate is about $89) and are looking to enhance your reading
experience, then I highly suggest you consider purchasing an e-reader.
E-readers are replacing the books of old, and I welcome them with open arms (as
you should).
If you haven’t heard of an e-reader
and don’t know what it is, then please permit the following explanation. An
e-reader is a device that allows you to read e-books. An e-book is a
book-length publication in digital form, consisting of text, images, or both,
and produced on, published through, and readable on computers or other
electronic devices. Sometimes the equivalent of a conventional printed book,
e-books can also be born digital. The Oxford Dictionary or English defines the
e-book as “an electronic version of a printed book, “but e-book can and do
exist without any printed equivalent.
So now you know what an e-reader is.
But you still may be wondering why they put printed books to shame. E-readers
are superior to printed books because they save space, are environmentally friendly,
and provide helpful reading tips and tools that printed books do not.
E-readers are superior to printed
books because they save space. The average e-reader can store thousands of
digital book, providing a veritable library at your fingertips. What is more,
being the size and weight of a thin hardback, the e-reader itself is relatively
petite. It is easy to hold and can fit in a pocketbook or briefcase easily. This
makes handling ponderous behemoths such as War and Peace, Anna Karenina, and
Les Miserables a breeze. Perhaps the only drawback to the space-saving aspect
of an e-reader is that it requires you to find new things to put on your
shelves.
In addition, e-readers are superior
to books because they are environmentally friendly. The average novel is about
300 pages long. So, if a novel is printed 1000 times, it will use 300,000
pieces of paper. That’s a lot of paper! If there are about 80,000 pieces of
paper in a tree, this means it takes almost 4 trees to make these 1000 books.
Now, we know that the average bestseller sells about 20,000 copies per week.
That means that it takes over 300 trees each month to sustain this rate. And
for the super bestsellers, these figures increase dramatically. For example,
the Harry Potter book series has sold over 450 million copies. That’s about 2
million trees! Upon viewing these figures, it is not hard to grasp the severe
impact of printed books on the environment. Since e-reader use no trees, they
represent a significant amount of preservation in terms of the environment and
its resources.
Finally, e-reader are superior to
books because they provide helpful reading tips and tolls that printed books do
not. The typical e-reader allows its user to customize letter size, font, and
line spacing. It also allows highlighting and electronic bookmarking.
Furthermore, it grants users the ability to get an overview of a book and then
jump to a specific electronic bookmarking. Furthermore, it grants users the
ability to get an overview of a book and then jump to a specific location based
on that overview. While these are all nice features, perhaps the most helpful
of all is the ability to get dictionary definitions at the touch of a finger.
On even the most basic e-reader, users can conjure instant definitions without
having to hunt through a physical dictionary.
It can be seen that e-readers are
superior to printed books. They save space, are environmentally friendly, and
provide helpful reading tips and tools that printed books do not. So what good
are printed books? Well, they certainly make nice decorations.
According to the author, which of
the following reading tips and tools are offered by the e-reader?
I line spacing customization
II the ability to quickly jump to
the end of a book
III access to an online thesaurus at
the touch of a finger
The history of the modern world is a
record of highly varied activity, of incessant change, and of astonishing
achievement. The lives of men have, during the last few centuries, increasingly
diversified, their powers have greatly multiplied, their powers have greatly
multiplied, their horizon been enormously enlarged. New interests have arisen
in rich profusion to absorb attention and to provoke exertion. New aspirations
and new emotions have come to move the soul of men. Amid all the bewildering phenomena,
interest, in particular, has stood out in clear and growing pre-eminence, has expressed
itself in a multitude of ways and with an emphasis more and more pronounced,
namely, the determination of the race to gain a larger measure of freedom than
it has ever known before, freedom in the life of the intellect and spirit,
freedom in the realm of government and law, freedom in the sphere of economic
and social relationship. A passion that has prevailed so widely, that has transformed
the world so greatly, and is still transforming it, is one that surely merits
study and abundantly rewards it, its operations constitute the very pith and
marrow of modem history.
Not that this passion was unknown to
the long ages that proceeded the modern periods. The ancient Hebrews, the
ancient Greeks and Roman blazed the was leaving behind them a precious heritage
of accomplishments and suggestions and the men who were responsible for the
Renaissance of the fifteenth century and the Reformation of the sixteen century
contributed their imperishable part to this slow and difficult emancipation of
the human race. But it is in modern times the pace and vigour, the scope and
sweep of this liberal movement have so increased unquestionably as to dominate
the age, particularly the last three centuries that have registered great
triumphs of spirit.
In what areas do you think have the
powers of men greatly multiplied during the last few centuries?
This is the age of machine.
Machines are everywhere, in the fields, in the factory, in the home, In the
street, in the city, in the country, everywhere. To fly, it is not necessary to
have wings; there are machines. To swim under the sea, it is not necessary to
have gills; there are machines. To kill our fellowmen in over-whelming numbers,
there are machines. Petrol machines alone provide ten times more power than all
human beings in the world. In the busiest countries, each individual has six
hundred human slaves in his machines.
What
are the consequences of this abnormal power? Before the war, it looked as
though it might be possible, for the first time in history to provide food and
clothing and shelter for the teaming population of the world-every man, woman
and child. This would have been the greatest triumphs of science. And yet, if
you remember, we saw the world crammed, full of food and people hungry. Today,
the leaders are bare and millions, starving. That’s more begin to hum, are we
going to see again more and more food, and people still hungry? For the goods,
it makes the goods, but avoids the consequences.
What
would be one of the greatest triumphs of science?
The history of the modern world is a
record of highly varied activity, of incessant change, and of astonishing
achievement. The lives of men have, during the last few centuries, increasingly
diversified, their powers have greatly multiplied, their powers have greatly
multiplied, their horizon been enormously enlarged. New interests have arisen
in rich profusion to absorb attention and to provoke exertion. New aspirations
and new emotions have come to move the soul of men. Amid all the bewildering phenomena,
interest, in particular, has stood out in clear and growing pre-eminence, has expressed
itself in a multitude of ways and with an emphasis more and more pronounced,
namely, the determination of the race to gain a larger measure of freedom than
it has ever known before, freedom in the life of the intellect and spirit,
freedom in the realm of government and law, freedom in the sphere of economic
and social relationship. A passion that has prevailed so widely, that has transformed
the world so greatly, and is still transforming it, is one that surely merits
study and abundantly rewards it, its operations constitute the very pith and
marrow of modem history.
Not that this passion was unknown to
the long ages that proceeded the modern periods. The ancient Hebrews, the
ancient Greeks and Roman blazed the was leaving behind them a precious heritage
of accomplishments and suggestions and the men who were responsible for the
Renaissance of the fifteenth century and the Reformation of the sixteen century
contributed their imperishable part to this slow and difficult emancipation of
the human race. But it is in modern times the pace and vigour, the scope and
sweep of this liberal movement have so increased unquestionably as to dominate
the age, particularly the last three centuries that have registered great
triumphs of spirit.
The operation of which factor
constitutes the pith and marrow of modern history?
Lilly loves her town. She loves
the mall. She loves the parks. She also loves her school. Most of all, though,
Lilly loves the seasons. In her old town, it was hot all of the time.
Sometimes it is cold in Lilly’s
new town. The cold season is in winter. Once in a while it snows. Lilly has
never seen snow before. So far her, the snow is exciting as well as very
beautiful. Lilly has to wear gloves to keep her hands warm. She also wear a
scarf around her neck.
In spring, flowers bloom and the
trees turn green with new leaves. Pollen falls on the cars and windowsills and
makes Lilly sneeze. People work in their yards and mow their grass.
In summer, Lilly wears her old
shorts and sandals- the same ones she used to wear in her old town. It is hot
outside, and dogs lie in the shade. Lilly and her friends go to a pool or play
in the water sprinkler. Her father cooks hamburgers on the grill for dinner.
Lilly’s favorite season is autumn.
In autumn, the leaves on the trees turn yellow, gold, red, and orange.
Halloween comes in autumn, and this Lilly’s favorite holiday. Every Halloween,
Lilly wears a costume. Last year she wore a mouse costume. This year she will
wear a fish costume.
One evening in autumn, Lilly and
her mom are on sitting together on the porch. Mom tells Lilly that autumn is
also called “fall”. This is a good idea, Lilly thinks, because in the fall all
of the leaves fall down from the trees.
Based on information in paragraph
5, which of the following costumes is Lilly most likely to wear next year?
Although cynics may like to see he government’s policy for
women in terms of the party’s internal power struggles, it will nevertheless be
churlish to deny that it represents a pioneering effect aimed at bringing about
sweeping social reforms. In its language, scope and strategies, the policy documents
displays a degree of understanding of women’s needs that is uncommon in
government pronouncements. This is due in large part to the participatory
process that marked its formulation, seeking the active involvement right from
the start of women’s groups, academic institutions and non-government
organizations with grass roots experience. The result is not just a lofty
declaration of principles but a blueprint for a practical program of action.
The policy delineates a series of concrete measures to accord women a
decision-making role in the political domain and greater control over their
economic status. Of especially far-reaching impart are the devolution of
control of economic infrastructure to women, notably at the gram panchayat
level, and the amendment proposed in the Act of 1956 to give women comparcenary
rights.
And enlightened aspect of the policy is its recognition that
actual change in the status of women cannot be brought about by the mere enactment
of socially progressive legislation. Accordingly, it focuses on reorienting
development programs and sensitizing administrations to address specific
situations as, for instance, the growing number of households headed by women,
which is a consequence of rural-urban migration. The proposal to create an
equal-opportunity police force and give women greater control of police
stations is an acknowledgement of the biases and callousness displayed by the
generally all-male law-enforcement authorities in case of dowery and domestic
violence. While the mere enunciation of such a policy has the salutary effect
of sensitizing the administration as a whole, it does not make the task of its
implementation any easier. This is because the changes it envisages in the
political and economic status of woman strike at the root of power structures
in society and the basis of man-woman relationship. There is also the danger
that reservation for women in public life, while necessary for their greater
visibility, could lapse into tokenism or become a tool in the hands of vote
seeking politicians. Much will depend on the dissemination of the policy and
the ability of elected representatives and government agencies to reorder their
priorities.
According to the passage which of the following is not true?
Fleas are perfectly designed by
nature to feast on anything containing blood. Like a shark in the water or a
wolf in the woods, fleas are ideally equipped to do what they do, making them
very difficult to defeat. The bodies of these tiny parasites are extremely
hardy and well-suited for their job.
A flea has a very hard exoskeleton,
which means the body is covered by a tough, tile-like plate called a sclerite.
Because of these plates, fleas are almost impossible to squish. The
exoskeletons of fleas are also waterproof of fleas are also waterproof and shock
resistant, and therefore fleas are highly resistant to the sprays and chemicals
used to kill them.
Little spines are attached to his
plate. The spine the flea scurries through an animal’s fur in – search of
grooming pet tries to pull a flea off through the hair coat, these spines will
extend and stick to the fur like Velcro.
Fleas are some of the best jumpers
in the natural world. A flea can jump seven inches, or 150 times its own
length, either vertically or horizontally. An equivalent jump for a person
would be 555 feet, the height of the Washington Monument. Fleas can jump 30,000
times in a row without stopping, and they are able to accelerate through the
air at an incredibly high rate – a rate which is over ten times what humans can
withstand in an airplane.
Fleas have very long rear legs with
huge thigh muscles and multiple joints. When they get ready to jump. They fold their
long legs up and crouch like a runner on a staring block. Several of their
joints contain a protein called resilin, which helps catapult fleas into the
air as they jump, similar to the way a rubber band provides momentum to a
slingshot. Outward facing claws on the bottom of their legs grip anything they
touch when they land.
The adult female flea mates after
her first blood meal and begins producing eggs in just 1 to 2 days. One flea
can lay up to 50 eggs in one day and over 2,000 in her lifetime. Flea eggs can
be seen with the naked eye, but they are about the size of a grain of salt. Shortly
after being laid, the eggs begin to transform into cocoons. In the cocoon
state, fleas are fully developed adults, and will hatch immediately if
conditions are favorable. Fleas can detect warmth, movement, and carbon dioxide
in exhaled breath, and these three factors stimulate them to emerge as new
adults. If the flea does not detect appropriate conditions, it can remain
dormant in the cocoon state for extended periods. Under ideal conditions, the
entire life cycle may only take 3 weeks, so in no time at all, pets and homes
can become infested.
Because of these characteristics,
fleas are intimidating opponents. The best way to control fleas, therefore, is
to take steps to prevent an infestation from ever occurring.
According to the passage, which of
the following statements is true?