Question

If a noisy neighbor is blasting music at all hours of the day and night, drowning out your phone conversations and interrupting your sleep, you can call the police. But what is a whale to do?
Natural noise from waves, wind, rain and even earthquakes is common in oceans. Unfortunately, man-made noise from oil and gas drilling, sonar, and ships is also present.
Low frequency noise has doubled off the California coast every decade since the nineteen sixties. The main reasons are ships’ propellers(螺旋桨). They not only generate continuous low frequency sound, some propellers cavitate(形成气穴), which means they create air bubbles that collapse, creating loud popping sounds.
Whales use low frequency calls to communicate across thousands of miles of ocean. They are threatened by noise pollution because it can prevent them from contacting each other and from locating their foods. Endangered humpback and right whales, which use fibrous baleen to strain food from the water, are the most at risk.

Scientists studying right whales off Canada’s east coast have discovered that whales are sending louder calls through the water to make themselves heard. Because they invest more energy in making calls, they have less energy available for finding food and mating. Other scientists measuring whale calls against background noise pollution have discovered that right whales have lost about eighty percent of their normal communication area. This could seriously affect survival of this already threatened species.
Scientists don’t have badges and guns, but they are trying to correct the noise pollution problem. By tracking ships and marine mammals and understanding how noise travels, they are creating sound maps. They hope to get shipping lanes moved so that the noise pollution ships create will not overlap with areas most important to the whales.

71. What does the passage mainly talk about?

A. Whales are in danger because of the noise.　　　　　　

B. Noise pollution is affecting whales.

C. Natural noise is good for whales.　　　　　　　　　　　　

D. How to protect whales endangered.

72. The following statements are true EXCEPT ________.

A. You can call the police if you are disturbed by a noise neighbor

B. Low frequency noise has doubled off the Canadian coast every decade since 1960s.

C. Noise pollution can prevent whales from contacting each other and from locating prey.

D. Endangered humpback and right whales are the most at risk.

73. We can infer from the last paragraph that ________.

A. Some areas important to whales are overlapped with the ship lanes.

B. Scientists are creating the sound maps by tracking ships and marine mammals.

C. If scientists have guns, they can correct the noise pollution.

D. Scientists have worked out a plan to protect the whales.

74. According to scientists, ________.

A. Right whales off the Californian coast have been in danger because of the loss of the energy.

B. Right whales cannot find food and mate for they lose a lot of living area.

C. There are about 20% of the normal communication areas still available for the right whales.

D. The right whales always invest most of their energy for making calls.

75. According to the description of whales, we can know that ________.

A. The noise made by the ships has a bad effect on the area where whales live.

B. Whales can communicate with each other by diving into the deep water.

C. Whales cannot find mates because they don’t have enough energy.

D. The communication between whales is through low frequency calls

　　　　　　　　　　　　

Answer 1

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