阅读理解

　　People realize that although animals may not have the same intelligence as human beings, they are smart enough to learn certain things.

　　Dogs are extremely useful as companions for blind people. When a dog has been properly trained, he will always lead his blind master in the right direction and kept him out of danger. For example, seeing－eyes dogs learn never to cross a busy road when cars are coming, even if their masters command(命令) them to do so.

　　Horses are also able to learn many things. Horses that are used for guard or police duty must learn never to be frightened of noises, traffic, and other disturbances. Racing horses are able to run much farther than other horses, but they are also quite high strung(紧张的). Therefore, it is necessary for those people who train them to be very patient and understanding.

　　The moving pictures and television can be used to train animals. Some animals such as monkeys and foxes, are easy to film. All you have to do is to make a trail in front of the camera by dragging something that smells good to the animals over the ground. Big animals, such as lions and tigers, can be photographed as they hound(狩猎；追捕) happily back to their families and dinner. If a movie actor is near, the well－trained animal will pay no attention to him. However, the audience may imagine that the actor escaped a terrible death by the skip(遗漏) of his teeth.

1．Dogs who help blind people must learn ________.

[　　]

A．to obey all others

B．to obey any safe orders

C．never to cross busy roads

D．to cross roads when commanded to do so

2．Race horses are hard to train because they are ________.

[　　]

A．faster than other horses

B．smaller than other horses

C．cleverer than other horses

D．more nervous than other horses

3．What does “make a trail” mean here in the last paragraph ________.

[　　]

A．place some thing to attract the animal

B．give the animal a certain task

C．order the animal to do things

D．follow the animal to hurt

4．Lions can be photographed easily when ________.

[　　]

A．they are following a trail of something that smells good to them

B．they are returning to their families

C．they have been trained to work with other animals

D．they do not know a movie－actor is nearly