Some scientists say that animals in the ocean are increasingly threatened by noise pollution caused by human beings.
Decibels measured in water are different from those measured on land. A noise of one hundred-twenty decibels on land causes pain to human ears. In water, a decibel level of one-hundred ninety-five would have the same effect.
A team of American and Canadian scientists discovered that louder noises can seriously injure some animals. The research team found that powerful underwater explosions were causing whales in the area to lose their hearing. This 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 .
31 According to the passage, which of the following is increasingly dangerous to sea creatures?
B The sound of voices.
D The sound of steps.
A sounds made by animals themselves.
C underwater earthquakes.
33 Which of the following is discussed in the third paragraph?
B Different places may have different types of noises.
D Different ocean animals may have different reactions to noises.
A They wont be confused by noises.
C Their ability to reproduce will be lowered by high-level noises.
35 According to the passage, what will scientists most probably do in the future?
B They will protect animals from harmful noises.
D They will study the effect of ocean noise pollution.