For centuries, dolphins have got our admiration, and it is easy to see why. They are beautiful, cute and smart sea animals. Dolphins are not fish, but warm-blooded animals. They live in groups, and speak to each other in their own language. In this way, they are like other animals, such as bees and birds. But dolphins are very different from almost all land animals. It is said that dolphins are the world’s second smartest creatures after humans and have many brain features (特征) related to intelligence. Their brain is nearly the same size as our own, and they live a long time － at least twenty or thirty years.
Like some animals, dolphins use sound to help them find their way around. They also make these sounds to talk to each other and to help them find food. We now know they do not use their ears to receive these sounds, but the lower part of the mouth, called the jaw.
Strangely, dolphins seem to like man, and for thousands of years there have been stories about the dolphin and its friendship with people.
There is a story about sailors in the 19th century. In a dangerous part of the sea off the coast of New Zealand, they learnt to look for a dolphin called Jack. From 1871 to 1903, Jack met every boat in the area and showed it the way. Then in 1903 a passenger on a boat called The Penguin shot and wounded Jack. He recovered and for nine years more continued to guide all ships through the area － except for The Penguin.
Today, some people continue to kill dolphins, but many countries of the world now protect them and in these places it is against the law to kill them.
28．Dolphins are different from many other animals because they _____.
A．live in groups B．have their own language
C．are warm-blooded D．have large brains
 
29．Which of the following does the dolphin use to help it find its way around?
A．Its nose. B．Its ears.
C．Its jaw. D．Its eyes.
30．Why did the sailors off the coast of New Zealand look for Jack?
A．They wanted to kill Jack.
B．They wanted Jack’s help.
C．They wanted to take care of wounded Jack.
D．They enjoyed playing with Jack.
31．By telling the story of Jack, the writer wanted to show that _____.
A．dolphins are friendly and clever
B．people are cruel to animals
C．Jack is different from other dolphins
D．dolphins are being protected by all the countries
  28—31 DCBA