We gather a great amount of incidental knowledge from pets（宠物）. If we look after them properly, we learn what they like and dislike. We do not set out to gain this knowledge purposely, but in attending to our pets we gain it by the way. It is got without our realizing it.

In keeping our dogs or cats we learn about different diseases(疾病) that can affect them, and the cures for these diseases. We learn how much sleep they need and what kind of food keeps them healthy. In looking after our fish we learn about the composition of water. We get to know what kinds of fish can live peacefully together and what kinds are hostile to each other. We learn that animals, fish and birds have a lot of things in common with human beings.

If children keep pets, their general education is helped by this kind of incidental knowledge. One little incident after another in which their pets are involved adds to their store of learning. It is a more interesting form of learning than that given in the biology lesson in school. People who keep pets should have a sense of responsibility towards them. Children, too, should be taught to be responsible. Pets are completely dependent(依靠) on their owners and the owners should respond to this dependence by looking after them. Irresponsible behavior towards pets is a form of cruelty.

In deciding to keep a pet , we make ourselves responsible（有责任的）for providing proper food and shelter for the pet. In a crowded city like Hong Kong, where there is so little room for the exercise required by large pets, we should think twice before undertaking the responsibility of keeping one.

72.In keeping pets, we learn that ___________.

A. pets dislike human beings           B. pets share what we have

C. human beings can gain knowledge by keeping pets

D. pets and human beings gather a great amount of incidental knowledge

73.For children ___________ .

A. keeping pets widens(拓宽) their general knowledge

B. keeping pets adds to their trouble

C. all kinds of knowledge are gained by keeping pets

D. incidental knowledge is more important than general knowledge

74.In keeping pets, responsibility means ___________.

A. depending on them                                B. taking care of them

C. feeding them                                        D. teaching them

75.In Hong Kong, it is not proper to keep large pets because ___________.

A. they eat a lot while the owner provides little

B. they depend too much on people

C. there is little room for them to move aroundD. the responsibility is too great