Tom was ten years old and he was a very lazy boy. He didn’t like doing any work. He had to go to school, of course , but he didn’t study hard there and tried to do as little work as possible. His father and mother were both doctors and they hoped that their son would become one, too. But one day Tom said to his mother, “ When I finish school, I want to be a dustman.”
“A dustman?” his mother asked, she was very surprised. “ that’s not a very pleasant job, why do you want to be a dustman?”
“Because then I would only have to work one day a week.” Tom answered at once.
“Only one day a week?” his mother said, “What do you mean? And how do you know?”
“ Well,” Tom replied, “ I know that the dustmen who come to our house to work on Thursday, because I only see them on that day.”
根据短文内容，选择最佳答案，并在答题卷上按要求作答。
小题1:What kind of boy was Tom?
A．Tom was a clever boy.
B．Tom was a lazy boy.
C．Tom worked very hard.
D．Tom was not polite.小题2:What were his father and mother?
A．His father was a doctor and his mother was a nurse.
B．His father was a worker and his mother was a doctor.
C．His father was a doctor and his mother was a doctor, too.
D．His father and mother were teachers.小题3:What did his parents want him to be when he grew up?
A．They wanted him to be a dustman.
B．They wanted him to be an officer.
C．They wanted him to be a doctor.
D．They wanted him to be a football player.小题4:What did Tom say he wanted to be when he grew up?
A．Tom said that he wanted to be a dustman.
B．Tom said that he wanted to be a teacher.
C．Tom said that he wanted to be a doctor.
D．Tom said that he wanted to be a singer.小题5:Why did Tom think that dustmen only worked one day a week?
A．Because Tom heard of this before.
B．Because one of the dustmen had told him before.
C．Because Tom had seen the dustmen only on Thursday at his house.
D．Because Tom’s mother told him.
上下牙槽骨的吸收变化是（）