题目内容：

When Mary Smith was a student, she always wanted to be a teacher because she liked ____. When she was twenty, she started to ____ in a small school. She was a good teacher, and she laughed a lot with the children ____ her class. They enjoyed ____ teaching.

One day, one of the girls said to her, “Miss Smith, ____ does the hair on a man’s head become white before his beard does?”

Mary laughed ____ answered, “I don’t know, Helen. Do you know?”

“I don’t know, Miss Smith,” said Helen. “But it happened to my ____.” The other children in the class laughed when they ___ this.

Then a boy said, “I ____, Miss Smith! The hair on a man’s head becomes white first because it’s sixteen years ____ than his beard.”

1.A. apples    B. children    C. vegetables    D. soccer

2.A. study    B. live    C. learn    D. teach

3.A. on    B. by    C. for    D. in

4.A. her    B. my    C. your    D. his

5.A. what    B. how    C. why    D. when

6.A. but    B. and    C. till    D. so

7.A. father    B. mother    C. aunt    D. sister

8.A. saw    B. listened    C. heard    D. looked

9.A. think    B. know    C. work    D. agree

10.A. bigger    B. smaller    C. older    D. younger