6．Apes can't use sticks ____ ．

A．if they are too young　 B．when they are full

C．unless they see them　 D．unless they find food

5．One of the main differences between human beings and animals is that ____ ．

A．animals can't walk with their feet　　　 B．animals can't think

C．people can do all that animals do　　　 D．people can live in the houses

4．The babies would “smile and speak ”at the lights because ____.

A．they succeeded in“ turning on” the lights　　 B．the sight of lights was interesting

C．they need not turn back to watch the lights

D．the lights were directly connected to some basic “drives”

B

Human beings act in a different way from that of animals just because they can think while animals cannot．Even the cleverest animals cannot do things which to us seem very simple and which small children，as soon as they learn to talk，would be able to do．

A German scientist，who made experiments for many years with big apes，found that his apes could use sticks as tools to pull down bananas which they could not reach．But they only used the stick to get a banana when both the stick and the banana were in view at the same time．If the banana was in front of them and the stick was behind them，they could not use the stick．They could not bear(记住)the banana in mind long enough to look around and pickup the stick and then use it．

The reason for this is clear．We have words for banana and stick which help us to think about these things when they are not in sight．Even a small child knowing the words“banana”and“stick” has an idea of their relationship and is able to think of“stick”together with“banana”and to remember this long enough to pick up the stick from behind and use it on the banana．

Unable to speak，animals cannot keep their knowledge for long．That is why they often interrupt one line of action to do something else and later forget it completely．Human beings，on the other hand，use language and are able to go after one thing continuously and do it with a definite(明确的)aim．

3．In Papousek's experiment babies make learned movements of the head in order to ____ ．

A．be pleased　　　　　　 B．please their parents

C．be rewarded with milk　 D．have the lights turned on

2．Papousek noticed in his studies that a baby ____．

A．would make learned responses when it saw the milk

B．would continue the simple movements without being given milk

C．would turn its head to right or left when it had enough to drink

D．would carry out learned movements when it had enough to drink

1．According to the writer，babies learn to do things which ____.

A．will satisfy their surprise　　　　　 B．will meet their physical needs

C．are directly connected to pleasure　 D．will bring them a feeling of success

20．The writer of this passage seems to show us his worry that ____ .

A．dangerous animals will kill more people over the world

B．some animals will disappear if people destroy their living places

C．modern technology will destroy the balance of nature

　　 D．people will spend too much money on keeping pets

19．According to some psychologists' opinion we can find that ____ .

A．dogs and cats used to be the most popular pets

B．without animals human beings would feel lonely

C．it is not right for human beings to control nature

D．modern people should prefer dangerous animals to dogs and cats

18．Which may be the effective way to stop people catching animals from forests？

A．Stopping people cutting trees in forests．

B．Separating baby animals from their mothers．

C．Making people know the danger of their action．

D．Providing hunters with other jobs．

17．It can be concluded from this passage that ____ ．

A．keeping pets is very popular all over the world

B．keeping pets is very popular in some poor countries

C．keeping pets is against law in some rich countries

D．keeping pets costs a lot of money in some countries