DMany people thought babies were not able to learn things until they were five or six months old. But doctors now say babies begin learning on their first day of life. A baby will smile if his or her mother does something the baby likes. A baby learns to get the best care by smiling to please her mother or other care givers. This is when babies learn to connect and "talk" with other people.Language skills are believed to develop best in the first three years when the place is rich with sounds and sights. Scientists say children should hear the speech and language of other people again and again. The first signs of communication（交际）happen during the first few days of life , when a baby learns that crying will bring food and attention.Research shows that most children recognize the general sounds of their native language by six months of age. By that time, a baby usually begins to make sounds. By the end of their first year, most children are able to say a few simple words，although they may not understand the meaning of the words. By 18 months of age, most children can say between eight and ten words. By two years of age, most children are able to make simple sentences. By ages three, four and five, the number of words a child can understand quickly increases. It is at these ages that children begin to understand the rules of language.Babies will smile when _____.
A.they are wet or hungry B.they want to get the best care C.they want to talk to others D.they learn sounds and words正确答案B
