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问题 多选题

关于磁感应强度的理解，以下说法正确的是（　　）

A．由B=

F
IL
可知，电流为1A、长为1m的通电导线在匀强磁场中受力为1N时，则匀强磁场的磁感应强度大小就是1T

B．磁场中一小段通电导线所受安培力的方向就是该点磁感应强度的方向

C．小磁针在磁场中静止时北极所指的方向就是该点磁感应强度的方向

D．磁场中某点的磁感应强度与该点是否放通电导线无关

答案

A、由B=

F
IL
可知，电流为1A、长为1m的通电导线在匀强磁场中受力为1N时，而匀强磁场的磁感应强度大小不一定是1T，原因是导线是否垂直与磁场放置，故A错误，

B、根据左手定则，安培力的方向与电流方向、磁场方向垂直，安培力的方向与磁场方向不同．故B错误．

C、小磁针在磁场中静止时北极所指的方向就是该点磁感应强度的方向，故C正确．

D、磁感应强度的定义式为B=

F
IL
，大小与F合IL无关，由磁场本身性质决定，与是否放通电导线无关，故D正确；

故选：CD．

单项选择题

男，43岁，头痛半年余，MRI检查如图，最可能的诊断为（）

A.脑梗死

B.多发性结节性硬化

C.转移瘤

D.脑实质型脑囊虫病

E.脑囊肿
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写作题

阅读下面的短文，然后按照要求写一篇150词左右的英语短文。

As Guangzhou is accelerating its preparation for the 2010 Asian Games, Guangzhou citizens in every field are making an endeavor to help the host city take on a new look. On the 5th of January, Mayor Zhang Guangning announced that the government is considering giving its people a big Asian Games present as a reward for their cooperation and devotion to the Games. As to what the present would be, relevant departments would collect ideas from the citizens.

This good news has brought about great guesses among Guangzhou people. Thus various opinions have emerged. Some prefer to have several days’ holiday as a reward, while others hope to receive the tickets to the events in the Asian Games. Sports lovers are eager to have free access to city stadiums. Some opportunists suggest the government hand out lottery tickets, in which case they may have the chance to win a big fortune. In contrast, those who hold a down-to-earth attitude are looking forward to some new year lucky money or to have more discounts when taking buses or the subway. For apartment hunters in their 20s or 30s, nothing can be more comforting than the thought of being able to buy an Asian Games Village apartment at a reasonable and acceptable price.

[写作内容]

1. 约30个词概括短文的要点；

2. 然后以约120个词写一篇文章，并包括以下要点：

1）你对政府给市民发送亚运大礼包的看法；

2）你想要政府送什么样的亚运大礼？为什么？

[写作要求]

1. 可以参照阅读材料，但不得直接引用原文中的句子；

2. 不得出现真实姓名和学校名称。

[评分标准] 概括准确，语言规范，内容合适，篇章连贯。
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