阅读短文，根据意思，从各题所给的A、B和C三个选项中选出最佳答案。并在答题卡上将该编号字母涂黑。
Can animals be made to work for us? Some scientists think that one day animals may be taught to do a number of simple jobs. They say that in a film or on TV .We may see elephants, or monkeys, dogs, bears, or other animals doing a lot of things. If you watch carefully, you may find that those animals are always given something to eat in return(作为回报) for doing them. The scientists say that many different animals may be taught to do a number of simple jobs if they know they will get something to eat in return.
Of course, as we know, dogs can be used to guard a house, and elephants can be used to do some heavy jobs. And we can also teach animals to work in factories. Apes(猿猴), for example, have been used in America to help make cars and scientists believe that these large monkeys may one day get in crops(收割庄稼) and even drive trains.
Elephant scan be used to do some heavy jobs because ____.
A. they can eat a lot   B. they are very heavy, too    C. they are very strong
Dogs can be used to guard a house for his host because ____.
A. they are good at running    
B. they are very kind and friendly to people
C. they are brave enough to get the strangers(陌生人)and thieves away from the house
Many different animals may be taught to do some simple jobs if ____.
A. they have enough food to eat             
B. if they are sent to school                               
C. they learn they will get something to eat in return after doing them              
____ can be trained to work for us.
A. Only a few animals    B. A lot of animals    C. Few animals
Many scientists are working hard to ____.
A. make monkeys get in crops and drive trains
B. make monkeys guard houses like dogs
C. make bears get in crops