Unit 2 Cloning learning about language课时作业

Ⅰ.阅读理解

(2018·广东深圳新安中学期中)

　　Food storing is common in members of the crow(乌鸦) family.A new study tested the birds outside this naturally occurring behaviour，which may have evolved(进化)specifically because it gives crows a survival advantage.Some crow species are known to naturally use tools to recover food.So the researchers tested whether the birds could store and recover a tool so they could get it at their food after a gap of 17 hours-something we wouldn't expect them to do naturally.But they were able to instantly select the tool out of a number of unnecessary items.

　　In another experiment，the researchers taught crows to select a token(代币) from a number of items so that they could then exchange for food.Again，the birds then showed that they could plan for the future using this new behaviour.This is different from all of the previous studies in future planning，which have focused on naturally occurring behaviour.For example，we know that chimpanzees select，transport and save appropriate tools for future needs.

　　These studies have shown that animals can plan for the future-but they left an important question open for debate.Are animals only able to plan to use abilities that have evolved to give them a specific advantage，or can they flexibly and intelligently apply planning behaviour across various actions？Most critics would say the former，as the animals were tested in naturally occurring behaviours.

　　But the new research provides the first evidence that animal species can plan for the future using behaviour that doesn't typically occur in nature.This supports the view that at least some recognitive abilities in animals don't evolve just in response to specific problems.Instead，it suggests that animals can apply these behaviours flexibly across problems in a similar way to humans.We need to investigate how flexible behaviour evolved.Then we might be able to see how crows' ability to plan for the future fits in with their broader cognitive powers.

1．What's the new finding about some crows according to Paragraph 1?

A．They can store food.

B．They can use tools to recover food.

C．They can store and recover tools.

D．They can select and store food.

2．What are crows trained by scientists to do when given a token?

A．Reject it casually. B．Exchange it for food.

C．Save it as their food. D．Build a nest with it.

3．What do scientists think of the studies that animals can plan for the future?

A．They are controversial. B．They are disappointing.