阅读理解。

     Dolphins are not fish. They are mammals (哺乳动物).They live in groups and speak to each other in

their own language. But they are quite different from almost all land animals.  Their brain(大脑)is as big

as men's and they live a long life at least 20 or 30 years.

     Like some animals, dolphins use sounds to  help them  find their way around.   They also use these

sounds to talk to each other and to help them find food. They do  not use their ears to receive sounds,

but use the jaw--the lower part of the mouth.

      It is strange that dolphins are friendly to men,  and for thousands of  years, there are many stories

about dolphins and men. In the 19th century, in a dangerous part of  the sea near New Zealand,there

was a dolphin. The seamen liked him very much and gave him a very good name, Jack. From 1871 to

1903 ,Jack met every boat in the area and showed it the way. In 1903 a passenger on a boat with the

name of The Penguin shot and hurt Jack. Luckily the dolphin didn't die,  and after a  long time he was

well again. He guided the ships through the area for nine more years, but he  refused to help the boat

of the Penguin.

     Today, some people still kill dolphins, but many countries in the world now protect them. In these

places, people are not allowed to kill them.

1. The word "jaw" means_________in Chinese.                     

A.下颚

B.嘴巴

C.嘴唇

D.鼻子

2. How do dolphins find their way?

A. They use their noses to smell the way.

B. They use their ears to hear the sounds.

C. They use their eyes to see the way.

D. They use sounds to find the way.  

3. Who was Jack?

A. The writer.

B. A dolphin.

C. A seaman.

D. The passenger.

4. The dolphin guided the ships for about________.

A. 32 years

B. 9 years

C. 41 years

D. 23 years        

5. According to the passage, which of the following is NOT right?

A. Dolphins are not fish.

B. Dolphins don't live in groups.

C. Dolphins are kind and friendly to people.

D. Dolphins can live a long life.