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.
Based on the information in
paragraph 2, we can understand that
I male mosquitoes and female mosquitoes have different
eating habits
II male mosquitoes are harmless to
humans
III female mosquitoes are
responsible for transmitting disease to humans
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.
At what time history did the liberal
movement enjoys its heyday?
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.
Which of the following is not true of the genetic
engineering movement?
