阅读下面短文，掌握其大意，然后从36-55各题所给的[A]、[B]、[C]、[D]四个选项中选出最佳答案。

If you travel in some areas in India, you will be lucky enough to be waited on by special guide-monkeys. (36) in waistcoat (马甲) ,these monkeys are always (37) to be of service to you. Hungry, you only have to point to your own (38) and they will lead you to the (39) . (40) the service is done. They’re just (41) for a little money as a tip. After that, they (42) their hands as if they were saying good-bye to you. (43) it or not, the monkeys are from the School for Monkeys in India, (44) they were trained for one year to (45) their diplomas (毕业证). They’re not the only monkey students in the world. Some are now being trained (46) nurses in an American (47) college. A (48) monkey named Helen has learned to (49) on and off the light, use a recorder and open doors and windows when he is (50) to. In the tropical (热带的) Malaysia where coconut trees (椰子树) (51) high up to the sky, monkeys would jump to the top and (52) off the coconuts for people. (53) the job is done, they would rush to their , (54) to get some wild (55) as rewards (奖赏).