下列说法中正确的是[ ] A.若置于匀强磁场中的导体长度和通过的电流一定,则导体

题型:不定项选择

问题:

下列说法中正确的是[ ]

A.若置于匀强磁场中的导体长度和通过的电流一定,则导体所受的安培力大小也一定

B.运动电荷之间的相互作用除了有电场力外还可能有磁场力

C.地磁场对垂直射向地面的宇宙射线的阻挡作用在南、北两极最强

D.磁场中某点磁场方向与可以自由转动的小磁针在该点静止时N极所指的方向相同

考点:磁场对通电导线的作用:安培力、左手定则磁场对运动电荷的作用:洛伦兹力、左手定则磁场,地磁场
题型:不定项选择

在X企业因财务状况的恶化,濒临破产之际,Y企业因X企业拥有良好的客户资源决定对其注资,Y企业在注资前要求对X企业进行全面清查。()

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Monday morning is an important time at our school. All of the students go to the playground. We listen to the music, and we      the national flag(国旗) go up.
Usually, one student gives a talk on Monday mornings. One Monday last year, a boy gave the talk. He was      and excited! When I saw him, I wanted to have a try, too. Can I really do it? 
Last week, our teacher said our class should give the talk. My teacher      me, "I know you want to have a try. Next Monday, you can give the talk. Go and write something down.        for it, I'm sure you'll do well." "Thank you ," I answered.It was such a great      for me !
When I got home , I was excited. I wrote two pages for the talk. I read them again and again. When I read, I asked my parents     me. I wanted to do my best to make it perfect .
Monday morning came. I began to feel       . When did I last give a talk to     many people?
Never! This was my first time. Could I really       it? Maybe I couldn't finish the talk.
When I got to school, we all went out to playground. I      in front of everyone. I opened my mouth, but I couldn't say anything. "Take it easy," I said to      . ”Don’t be nervous. You can do it."
Just then, I looked down at everyone. I saw about 1,000 eyes. They were all looking at me !
I couldn't      stand up. I looked at their eyes more carefully. Their eyes were saying , "You can do it! Don't be afraid, just talk !" I       a big breath. Then I began to talk.It wasn't hard. It was easy. I don't know       I finished my talk. But I did it. I felt so good that day. I showed myself      everyone what I can do.
小题1:
A.watch B.seeC.notice D.lookat
小题2:
A.surprising B.proudC.amazed D.careful
小题3:
A.told B.askedfor C.saidto D.showed
小题4:
A.Lookout B.Comeon C.Takecare D.Getready
小题5:
A.chanceB.news C.time D.message
小题6:
A.tolistento B.tolistenC.listento D.listen
小题7:
A.excited B.happy C.nervous D.surprised
小题8:
A.after B.suchC.before D.so
小题9:
A.do B.speak C.talk D.take
小题10:
A.stand B.stoodC.wasstanding D.havestood
小题11:
A.me B.myclass C.myself D.myparents
小题12:
A.beableto B.hardly C.ever D.even
小题13:
A.took B.held C.put D.left
小题14:
A.when B.howC.why D.whether
小题15:
A.so B.but C.to D.for
题型:不定项选择
已知|
a
|=4,|
b
|=3,且(2
a
-3
b
)•(2
a
+
b
)=61

(1)求
a
b
的夹角

(2)若
AB
=
a
AC
=
b
,求|
BC
|
题型:不定项选择

试述尾水管扩散段根据墩子与底板的连接方式可分为哪几种形型?各适用于什么条件?

题型:不定项选择

定向耦合器

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