Can animals be made to work for us?Some scientists think that on

Can animals be made to work for us?Some scientists think that one day animals may be trained to do a number of simple jobs that are now done by human beings. They point out that at a circus,for example,we may see elephants,monkeys,dogs and other animals doing quite skillful things．Perhaps you have seen them on the television or in a film．If you watch closely,you may notice that the trainer always gives the animal a piece of candy or a piece of fruit as a reward．The scientists say that many different animals may be trained to do a number of simple jobs if they know they will get a reward for doing them. Of course,as we know,dogs can be used to guard a house,and soldiers in both old and modem times have used geese to give warning by making a lot of noise when a stranger or an enemy comes near．But it may be possible to train animals to work in factories．In Russia,for example,pigeons which are birds with good eyesight,are being used to watch out for faults in small steel balls that are being made in one factory．When the pigeon sees a ball which looks different from others,it touches a steel plate with its beak．This turns on a light to warn people in the factory．At the same time a few seeds are given as a reward．It takes three to five weeks to train a pigeon to do this and one pigeon can inspect 3 000 to 4 000 balls an hour. Apes have been used in America in helping to make cars,and scientists believe that these large monkeys may be one day gather crops and even drive trains. Many animals may be trained to do simple jobs if they know__.
A、who their trainers are
B、they will be praised by theft trainers
C、they will get a reward
D、something dangerous will happen to them
【正确答案】：C
【题目解析】：从文章的内容可以看出，科学家们认为动物可以被训练来执行一些简单的任务，只要它们知道完成这些任务后会有奖励。在文章第二段中明确提到：“The scientists say that many different animals may be trained to do a number of simple jobs if they know they will get a reward for doing them.” 这句话直接支持了选项C。 文章还通过具体例子来说明这一点。例如，在第三段中，提到了在俄罗斯，鸽子被用来检查工厂中制造的小钢球是否有缺陷，当鸽子发现不同的钢球时，它会用喙触碰钢板，从而启动警告灯，并因此获得一些种子作为奖励。这个例子进一步强调了奖励在训练动物执行简单任务中的重要性。 因此，正确答案是C，即“they will get a reward”。