Directions: Read the following three passages．Each passage is followed by several questions or unfinished statements．For each of them there are four choices marked A, B, C and D．Choose the one that fits best according to the information given in the passage．
A
Some scientists say that animals in the oceans 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 one hundred and twenty decibels on land causes pain to human ears. In water, a decibel level of one hundred and ninety-five would
