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, fleas are
able to jump
I with a high rate of acceleration
II up and down and from side to side
III because the blood they eat
contains resilin
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 5, which is
the best synonym for ambiguous?
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
As used in paragraph 3, which is
the best synonym for ”purchase”?
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?
The history of literature really began was the earliest of
the arts. Man danced for joy round his primitive camp fire after the defeat and
slaughter of his enemy. He yelled and shouted as he danced and gradually the
yells and shouts became coherent and caught the measure of the coherent and
caught the measure of the dance and thus the first war song was sung. As the
idea of God developed prayers were framed. The songs and prayers became
traditional and were repeated from one generation to another, each generation
adding something of its own. As man slowly grew more civilized, he was
compelled to invent some method of writing by three urgent necessities. There
were certain things that it was dangerous to forget and which, therefore, had
to be recorded. It was often necessary to communicate with person who were some
distance away and it was necessary to protect one’s property by making tools,
cattle and so on, in some distinctive manner. So man taught himself to write
and having learned to write purely for utilitarian reasons he used this new
method for preserving his war songs and his prayers. Of course, among these
ancient peoples, There were only a very few individuals who learned to write,
and only a few could read what was written.
Main invented writing because he wanted
Recent advances in science and technology have made it
possible for geneticists to find out abnormalities in the unborn foetus and
take remedial action to rectify some defects which would otherwise prove to be
fatal to the child. Though genetic engineering is still at its infancy,
scientists can now predict with greater accuracy a genetic disorder. It is not
yet an exact science since they are not in a position to predict when exactly a
genetic disorder will set in. While they have not yet been able to change the
genetic order of the gene in germs, they are optimistic and are holding out
that in the near future they might be successful in achieving this feat. They
have, however, acquired the ability in manipulating tissue cells. However,
genetic mis-information can sometimes be damaging for it may adversely affect
people psychologically. Genetic information may lead to a tendency to brand
some people as inferiors. Genetic information can therefore be abused and its
application in deciding the sex of the foetus and its subsequent abortion is
now hotly debated on ethical lines. But on this issue geneticists cannot be
squarely blamed though this charge has often been leveled at them. It is mainly
a societal problem. At present genetic engineering is a costly process of
detecting disorders but scientists hope to reduce the costs when technology
becomes more advanced. This is why much progress in this area has been possible
in scientifically advanced and rich countries like the U.S.A., U.K. and Japan.
It remains to be seen if in the future this science will lead to the
development of a race of supermen or will be able to obliterate disease from
this world.
Why, according to the author, is genetic misinformation
severely damaging?
Sport shall be mentioned next. I have had a
liking for more than one form of sport, but an actual passion for salmon and
trout fishing. Salmon fishing, as I have enjoyed it, fishing not from a boat
but from one’s feet, either on the bank or wading deep in the stream, is a
glorious and sustained exercise for the whole body, as well as being an
exciting-sport; but many of my friends do not care for it. To them, I say, as
one who was fond of George Meredith’s Novels once said to be man who complained
that he should not read them, ‘why should you?’ if you do not care for fishing,
do not fish. Why should you? But if we are to be one equal term and you are be
one the same happy level as I hav3e been, then find something for yourself
which you like as much as I like fishing.
The writer recommends game for the youth which
test the: