Carol and Susan are very good friends. They are in the same class at school and they often go to each other’s home on Sunday. Now they are both eight yeas old. Carol’s mother has got a new baby. Carol is very glad to have a little sister, so she is always talking about her to Susan.
At first Susan is very interested (感兴趣) in the new baby because she does not have any brothers or sisters. But after some time she begins to get tired of (厌倦) Carol’s keeping on talking about it. She also feels a little jealous (嫉妒) of her friend.
One morning when the two girls meet at the school gate, Carol says to Susan cheerfully (愉快地), “Do you know, Susan, my baby sister has put on about half a pound in weight (重量) this week?”
“That is not very much,” answers Carol. “I know a baby that puts on ten pounds a day.”
“Oh, that can’t be true!” answers Carol. "Whose baby is it?”
“An elephant’s,” says Susan.
Why do Carol and Susan often go to each other’s home? Because ________.

A．they are in the same class

B．they are good friends

C．they like to talk about babies

D．they are in the same study group

Susan is ______ to hear Carol talk about the baby’s weight one morning.

A．sorry

B．cheerful

C．happy

D．not happy

How much does a baby elephant put on in weight a week?

A．Half a pound.	B．Ten pounds.
C．Seventy pounds.	D．Seven hundred pounds.