18.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,bear,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 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 elephant c an be used to do some heavy jobs.And we can also teach animal 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 (收割)crops and even drive trains.
25.Dogs can be used to guard a house for his host becauseC.
A.they are good at running
B.they are very kind and friendly to people
C.they are brave enough to get the stranger(陌生人)and thieves away from the house
D.they are clever
26.Many different animals may be taught to do some simple jobs ifB.
A.they have enough food to eat
B.they learn they will get something to eat in return after doing them
C.if they are sent to school
D.they are wise
27.Bcan be trained to work for us.
A.Only a few animals B.Quite a few animals
C.Few animals D.No animal
28.Many scientists are working hard toA.
A.make monkeys get in crops and drive trains
B.make monkeys guard house like dogs
C.make bears get in crops
D make monkeys clever.