When we are young, we learn that
tigers and sharks are dangerous animals. We might be scared of them because
they are big and powerful. As we get older, however, we learn that sometimes
the most dangerous animals are also the smallest animals. In fact, the animal
that kills the most people every year is one that you have probably killed
yourself many times: the mosquito.
While it may seem that all
mosquitoes are biters, this is not actually the case. Male mosquitoes eat plant
nectar. One the other hand, female mosquitoes feed on animal blood. They need
this blood to live and produce eggs. When a female mosquito bites a human
being, it transmits a small amount of saliva into the blood. The saliva may or
may not contain a deadly disease. The result of the bite can be as minor as an
itchy bump or as serious as death.
Because a mosquito can bite many
people in the course of its life, it can carry diseases from one person to
another very easily. Two of the most deadly diseases carried by mosquitoes are
malaria and yellow fever. More than 700 million people become sick from these
diseases every year. At least 2 million of these people will die from these
diseases.
Many scientists are working on
safer and better ways to kill mosquitoes, but so far, there is no sure way to
protect everyone in the world from their deadly bites. Mosquito nests can be
placed over beds to protect people against being bitten. These nets help people
stay safe at night, but they do not kill any mosquitoes. Mosquitoes have many
natural enemies like bats, birds, dragonflies, and certain kinds of fish.
Bringing more of these animals into places where mosquitoes live might help to
cut down the amount of mosquitoes in that area. This is a natural solution, but
is does not always work very well. Mosquitoes can also be killed with poisons
or sprays. Even though these sprays kill mosquitoes, they may also harm other
plants or animals.
Although mosquitoes may not seem
as scary as larger, more powerful animals, they are far more dangerous to human
beings. But things are changing. It is highly likely that one day scientists
will find a way to keep everyone safe from mosquitoes and the diseases they
carry.
Which of the following words best
described the author’s overall attitude towards the prospect of solving the
mosquito problem?
On January 3, 1961, nine days after
Christmas, Richard Legg, John Byrnes, and Richard McKinley were killed in a
remote desert in eastern Idaho. Their deaths occurred when a nuclear reactor
exploded at a top-secret base in the National Reactor Testing Station (NRTS).
Official reports state that the explosion and subsequent reactor meltdown
resulted from the improper retraction of the control rod. When questioned about
the events that occurred there, officials were very reticent. The whole affair,
in fact, was discussed much, and seemed to disappear with time.
In order to grasp the mysterious
nature of the NRTS catastrophe, it help to know a bit about how nuclear
reactors work. After all, the generation of nuclear energy may strike many as
an esoteric process. However, given its relative simplicity, the way in which
the NRTS reactor functions is widely comprehensible. In this particular kind of
reactor, a cluster of nine-ton uranium fuel rods are positioned lengthwise
around a central control rod. The reaction begins with the slow removal of the
control ro, which starts a controlled nuclear reaction and begins to heat the
water in the reactor. This heat generates steam, which builds pressure inside
the tank. As pressure builds, the steam looks for a place to escape. The only
place this steam is able to escape is through the turbine. As it passes through
the turbine on its way out of the tank, it turns the giant fan blades and
produces energy.
On the morning of January 3, after
the machine had been shut down for the holidays, the three men arrived at the
station to restart the reactor. The control rod needed to be pulled out only
four inches to be reconnected to the automated driver. However, records
indicate that Byrnes yanked it out 23 inches, over five times the distance
necessary. In milliseconds the reactor exploded. Legg was impaled on the
ceiling; he would be discovered last. It took one week and a lead-shielded
crane to remove his body. Even in full protective gear, workers were only able
to work a minute at a time. The three men are buried in lead-lined coffins
under concrete in New York, Michigan, and Arlington Cemetery, Virginia.
The investigation took nearly two
years to complete. Did Byrnes have a dark motive? Or was it simply an accident?
Did he know how precarious the procedure was? Other operators were questioned
as to whether they knew the consequences of pulling the control rod out so far.
They responded “Of course! We often talked about what we would do if we were at
a radar station and the Russians came.
“We’d yank it out.”
Official reports are oddly
ambiguous, but what they do not explain, gossip does. Rumors had it that there
was tension between the men because Byrnes suspected the other two of being
involved with his young wife. There is little doubt than he, like the other
operators, knew exactly what would happen when he yanked the control rod.
As used in paragraph 4, which is
the best synonym for precarious?
