题目内容：

Not long ago, people thought babies were notable to learn things until they were five or six months old．Yet doctors in the United States say babies begin learning on their first day of life．

Scientists note that babies are strongly influenced by their environment．They say a baby will smile if her mother does something the baby likes．A baby learns to get the best care possible by smiling to please her mother or other caregiver．This is how babies learn to connect and communicate with other human beings．

One study shows that babies can learn before they are born．The researchers placed a tape recorder on the stomach of a pregnant woman．Then, they played a recording of a short story．On the day the baby was born, the researchers attempted to find if he knew the sounds of the story repeated while in his mother．They did this by placing a device in the mouth of the newborn baby．

The baby would hear the story if he moved his mouth one way．If the baby moved his mouth the other way, he would hear a different story．The researchers say the baby clearly liked the story he heard before he was born．They say the baby would move his mouth so he could hear the story again and again． 

Another study shows how mothers can strongly influence social development and language skills in their children．

Researchers studied the children from the age of one month to three years．The researchers attempted to measure the sensitivity of the mothers．The women were considered sensitive if they supported their children’s activities and did not interfere unnecessarily．They tested the children for thinking and language development when they were three years old．Also, the researchers observed the women for signs of depression．

The children of depressed women did not do as well in tests as the children of women who did not suffer from depression．The children of depressed women did poorly in tests of language skills and understanding what they hear．

These children also were less cooperative and had more problems dealing with other people．The researchers noted that the sensitivity of the mothers was important to the intelligence development of their children．Children did better when their mothers were caring, even when they suffered from depression．

1.What does the experiment in which newborn babies heard the stories prove?

（no more than 5 words）

2.In the passage, what factors are mentioned that influence intelligence development in babies?

（no more than 8 words）

3.Which group of children did the worst in tests of language skills?

（no more than 11 words）

4.What is the main idea of the passage?

（no more than 8 words）