题目内容：

D

A fish may not be the first creature that comes to mind when co-operation in the animal world is mentioned, but a new study has shown the caring behavior of one sea species. Scientists have found that pairs of rabbitfishes will help and support each other while feeding. While such behavior has been recorded for birds and mammals, it had formerly been thought to be impossible for fishes to exhibit the same features.

＂We found that rabbitfish pairs manage their caring activity quite firmly, thus providing safety for their partner that is looking for food,＂ says Dr. Simon Brandl. ＂In other words, one partner stays ‘on guard’ while the other feeds – these fishes just watch each others’ back,＂ Dr. Brandl says. ＂This behavior is so far unique among fishes and appears to be based on reciprocal cooperation between pair members.＂

Reciprocal cooperation, which requires an investment in a partner that is later reciprocated（报答）, is supposed to require complex cognitive and social skills — something that fishes had been considered not to have until now.

Dr. Brandl says the research shows clear support and presents interesting evidence for reciprocal support between the rabbitfish pairs.

＂There has been a long debate about whether reciprocal cooperation can exist in animals that lack the highly developed cognitive and social skills found in humans and a few species of birds and primates,＂ he said. ＂By showing that fishes — which are commonly considered to be cold, unsocial, and unintelligent — are able to have reciprocal cooperative systems, we provide evidence that cooperation may not be as special as earlier expected.＂

Professor Bellwood says that our opinion of fishes as cold creatures is slowly changing. ＂Our findings should further cause efforts to understand fishes as highly developed organisms with complex social behaviors. This may also require a change in how we study and treat fishes.＂

【题文1】 What does the first paragraph imply? 

A. Rabbitfishes almost act like birds and mammals.

B. Fishes don’t belong to the animal world at all.

C. Fishes have the ability to feed each other.

D. The caring behavior is impossible for fishes.

【题文2】While one rabbitfish feeds, the other one _________.

A. is protecting its partner from any danger      B. is carrying some food for its partner

C. is looking for more food for its partner      D. is hiding behind the back of its partner

【题文3】 What did people use to think about fishes?

A. They have the same behaviors.       B. They show no feelings for others.

C. They have high social skills.        D. They support each other all the time.

【题文4】What can we infer from what Bellwood said？

A. We should change our way of eating fish.    

B. The behaviors of fishes are difficult to learn.

C. More efforts are needed to understand fish.

D. Our study of social behaviors should be careful.