问题 单项选择题

线性表是一个______。

A.有限序列,可以为空
B.有限序列,不能为空
C.无限序列,可以为空
D.无限序列,不能为空

答案

参考答案:A

解析:如果一个非空的数据结构满足下列两个条件:第一,有且只有一个根结点;第二,每一个结点最多有一个前件,也最多有一个后件,则称该数据结构为线性结构。线性结构又称线性表。

阅读理解

阅读理解

       Tom arrived at the bus station quite early for Paris bus. The bus for Paris would not leave until five

to twelve. He saw a lot of people waiting in the station. Some were standing in line(排队), others were

walking around. There was a group of schoolgirls. Their teacher was trying to keep them in line. Tom

looked around but there was no place for him to sit.

       He walked into the station cafe(咖啡馆). he looked up at the clock there. It was only twenty to

twelve. He found a seat and sat down before a large mirror(镜子) on the wall. Just then, Mike, one

of Tom's workmates came in and sat with Tom.

       "What time is your bus?" asked Mike.

       "There's plenty of time yet," answered Tom.

       "Well, I'll get you some more tea then," said Mike.

       They talked while drinking. Then Tom looked at the clock again. "Oh! It's going backward(倒行)!"

he cried. "A few minutes ago it was twenty to twelve and now it's half past eleven."

       "You're looking at the clock in the mirror." said Mike. Tom was so sad(难过). The next bus was

not to leave for another hour. Since then Tom has never liked mirrors.

根据以上短文内容,从下列各题所给的四个选项中选择最佳的一项

1. Tom went into the station cafe because ________ .

A. Mike asked him to have a cup of tea

B. it was quite early and he could find a seat there

C. he didn't like to stay with the schoolgirls

D. he wanted to have a drink with his workmate there

2. What time was it in fact when Tom looked at the clock in the mirror?

A. Half past twelve  

B. Twenty past twelve

C. Half past eleven  

D. Half past one

3. From the story we know that when we look at a clock in a mirror, we will find  

A. the time is right  

B. it's going slower

C. it's going backward  

D. it's going faster

4. Which of the following is true?

A. Tom arrived in Paris on time

B. The next bus would leave in half an hour

C. After that Tom didn't like clocks any longer

D. Tom looked at the clock in the mirror only once

5. Which of the following is the title(题目) of the story?

A. The Mirror of the Station

B. Not A Careful Man

C. Missing A Bus

D. The Clock In The Mirror

多项选择题