Some scientists say that animals in the ocean are
increasingly threatened by noise pollution caused by human beings. The noise
that affects sea creatures comes from a number of human activities. It is
caused mainly by industrial underwater explosions, ocean drilling, and ship
engines. Such noises are added to natural sounds. These sounds include the
breaking of ice fields, underwater earthquakes, and sounds made by animals
themselves.
Decibels(分贝) measured
in water are different from those measured on land. A noise of 120 decibels on
land causes pain to human ears. In water, a decible level of 195 would have the
same effect.
Some scientists have suggested setting a noise limit
of 120 decibles in oceans. They have observed that noises above that level can
frighten and confuse whales.
A team of American and Canadian scientists discovered
that loud noises could seriously injure some animals. The research team found
that powerful underwater explosions were causing whales in the area to lose
their hearing, which seriously affected the whales’ ability to exchange
information and find their way. Some of the whales even died. The explosions
had caused their ears to bleed and become infected(感染的).
Many researches whose work depends on ocean sounds
disagree with a limit of 120 decibels. They say such a limit would mean an end
to important industrial and scientific research.
Scientists do not know how many and what kinds of
noises are harmful to ocean animals. However, many scientists suspect that
noise is a greater danger than they previously believed. They want to prevent
noises from harming creatures in the ocean.
1.The second paragraph mainly tells us that the noises
on land and in water .
A.are both from
human activities.
B.both do harm
to sea animals
C.are measured
differently
D.have the same
effect on humans
2.As to(依据) the
effects of noises on whales, which of the following statements is TRUE
according to the passage?
A.They are deaf
to noises.
B.Noises at a
certain level may hurt them.
C.They are
easily confused by noises.
D.Noises will
limit their ability to reproduce.
3.Many researchers think that the noise limit of 120
decibels would .
A.protect
whales from noises
B.benefit them
a lot in their research work
C.do good to
their health
D.increase
industrial output
4.What will scientists most probably do in the future?
A.Count the
number of sea animals.
B.Stop their
research on the ocean.
C.Study the
effect of different noises.
D.Protect sea
creatures from harmful noises.