The baby monkey is much more developed at birth than the human baby.Almost from the moment it is born，the baby monkey can move around and hold tightly to its mother.During the first few days of its life the baby will approach and hold onto almost any large，warm，and soft object in its environment，particularly if that object also gives it milk.After a week or so，however，the baby monkey begins to avoid newcomers and focuses its attentions on“mother”—the real mother or the mothersubstitute(母亲替代物)．
During the first two weeks of its life warmth is perhaps the most important psychological(心理的)thing that a monkey mother has to give to its baby.The Harlows，a couple who are both psychologists，discovered this fact by offering baby monkeys a choice of two types of mothersubstitutes—one covered with cloth and one made of bare wire.If the two artificial mothers were both the same temperature，the little monkeys always preferred the cloth mother.However，if the wire model was heated，while the cloth model was cool，for the first two weeks after birth the baby monkeys picked the warm wire mothersubstitutes as their favorites.Thereafter they switched and spent most of their time on the more comfortable cloth mother.
Why is cloth preferable to bare wire？Something that the Harlows called contact(接触)comfort seems to be the answer，and a most powerful influence it is.Baby monkeys spend much of their time rubbing against their mothers’ skins，putting themselves in as close contact with the parent as they can.Whenever the young animal is frightened，disturbed，or annoyed，it typically rushes to its mother and rubs itself against her body.Wire doesn’t “rub” as well as does soft cloth.Prolonged(长时间的)“contact comfort” with a cloth mother appears to give the babies confidence and is much more rewarding to them than is either warmth or milk.
According to the Harlows，the basic quality of a baby’s love for its mother is trust.If the baby is put into an unfamiliar playroom without its mother，the baby ignores the toys no matter how interesting they might be.It screams in terror and curls up into a furry little ball.If its cloth mother is now introduced into the playroom，the baby rushes to it and holds onto it for dear life.After a few minutes of contact comfort，it obviously begins to feel more secure.It then climbs down from the mothersubstitute and begins to explore the toys，but often rushes back for a deep embrace(拥抱)as if to make sure that its mother is still there and that all is well.Bit by bit its fears of the new environment are gone and it spends more and more time playing with the toys and less and less time holding onto its “mother”．
Psychologically，what does the baby monkey desire most during the first two weeks of its life?

A．Warmth.	B．Milk.
C．Contact.	D．Trust.

After the first two weeks of their life，baby monkeys prefer the cloth mother to the wire mother because the former is________.

A．larger in size

B．closer to them

C．less frightening and less disturbing

D．more comfortable to rub against

What does the baby monkey probably gain from prolonged“contact comfort”？

A．Attention.	B．Softness.
C．Confidence.	D．Interest.

It can be inferred that when the baby monkey feels secure，________.

A．it frequently rushes back for a deep embrace when exploring the toys

B．it spends more time screaming to get rewards

C．it is less attracted to the toys though they are interesting

D．it cares less about whether its mother is still around

The main purpose of the passage is to ________.

A．give the reasons for the experiment

B．present the findings of the experiment

C．introduce the method of the experiment

D．describe the process of the experiment