在CCTV“开心辞典”栏目中，主持人问这样一道题目：“a是最小的_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题选择题

在CCTV“开心辞典”栏目中，主持人问这样一道题目：“a是最小的正整数，b是最大的负整数，c是绝对值最小的有理数，请问：a，b，c三数之和是多少？”[ ]

A．-1

B．0

C．1

D．2

答案

答案：B

改错题

短文改错。
     按照要求改正所给短文中的错误，对标有题号的每一行作出判断：　
     如有错误（每行只有一个错误），则按下列情况改正：
     该行多一个词：把多余的词用斜线（＼）划掉，在该行右边横线上写出该词，并也用斜线划掉。
     该行缺一个词：在缺词处加一个漏字符号（^），在该行右边横线上写出该加的词。
     该行错一个词：在错的词下划一横线，在该行右边横线上写出改正后的词。
     注意：原行没有错的不要改。

Last Friday, I left my house to join in my friend Peter,
who was waiting for me in his car. While talked to him, I put
my purse, it had a lot of money in it, on the car roof and
went back my room for my glasses. Forgetting that
the purse was on a car roof, I got into the car and
we drove away. And the purse fell down. When I
discovered the loss, and I went to the police station.
It turns out that the finder of the purse was a farmer on
his way back. After returning to the city, she handed it
in to police. I thanked him for his honesty.

1. _____
2. _____
3. _____
4. _____
5. _____
6. _____
7. _____
8. _____
9. _____
10. _____

填空题

图中所示是检验磁场对通电导体作用力的实验装置．当导线ab中有某方向电流通过时，它受到磁场的作用力向上．

（1）如果仅将两磁极对调位置，导线ab受力向______；

（2）如果磁极位置不变仅改变ab中的电流方向，导线ab受力向______；

（3）如果同时对调磁极位置和改变电流方向，导线ab受力向______．