Question

【2011·江蘇溧陽中學模擬】D

       Ears are for hearing — everyone knows that. But for a creature called the Cuvier’s beaked whale, hearing starts in the throat, a new study found.

The observation might help explain how all whales hear. The work might also help scientists understand how animals are affected by underwater sonar (一種探測系統(tǒng)). This sonar, used by some ships, sends out sound waves to locate underwater objects.

The Cuvier’s beaked whale is a so-called toothed whale. Toothed whales dive deep into the ocean in search of food. As the whales hunt, they produce sounds that reach objects and then return to the whales. This allows the animals to “see” the shape, size, and location of objects, even when they’re 1,000 meters under the sea, where it is totally dark.

To better understand how the whale hears, researchers from San Diego State University in California took X-rays of two Cuvier’s beaked whales. The whales had died and washed up on the beach.

Ted Cranford and his colleagues used the images to make a computer model of a Cuvier’s beaked whale’s head. Then, they modeled the process of sound traveling through the head.

The researchers knew that some sounds get to the ears of a toothed whale through a structure  called “the window for sound”. Found on the lower jaw, this structure is very thin on the outside and has a large pad (墊) of fat on the inside.

When the researchers used their computer model to work out how sound waves travel in the whale’s head, they were surprised to find that sounds coming from right in front of the whale actually travel under the animal’s jaw. From there, sound waves move through the throat, into a hole in the back of the jaw, and finally to the pad of fat near the animal’s ears.

Cranford guesses that other types of whales may hear through their throats. Further testing is needed to be sure. Eventually, the insight into how whales hear might explain whether sonar testing by military ships is causing the animals to wind up on beaches.

67. Toothed whales look for food under the sea by ______.

  A. watching the shape and size of their objects    B. diving deep into the sea

  C. sending and receiving sounds                        D. making lots of noises     

68. Researchers took X-rays of two Cuvier’s beaked whales in order to ______.

  A. find out why they had died and washed up on the beach

  B. make a computer model of a Cuvier’s beaked whale’s head

  C. make sure that sound travels through the head

  D. know more about the way the whale hears   

69. Which of the following describes the way taken by sound waves through a Cuvier’s beaked whale?

  A. A hole in the back of the jaw → the ears → the jaw → the throat.   

  B. The jaw → the throat → a hole in the back of the jaw → the ears.

  C. The throat → the jaw → the ears → a hole in the back of the jaw.   

  D. The ears → the throat → a hole in the back of the jaw → the jaw.

70. What can be inferred from the last sentence of the passage?

  A. Ears are useless to the Cuvier’s beaked whale.

  B. Military ships send out sounds like a Cuvier’s beaked whale.

C. The whale’s unusual acts have nothing to do with human activities.

  D. Further research might show human activities can influence whale’s activities.

Answer 1

【答案】  CDBD