磁场是有方向的，小磁针在磁场中静止时，______极所指的方向规定为该点的磁场方

发布时间：2017-06-18 00:10 │ 来源：www.tikuol.com

题型：填空题

问题：

磁场是有方向的，小磁针在磁场中静止时，______极所指的方向规定为该点的磁场方向．通常用磁感线来描述磁场的_______ 和_______ ．磁体周围的磁感线是从它的_______ 极出来，回到它的________极．

考点：磁场、地磁场磁感线及其特点

题型：填空题

若等差数列{a_n}的前n项和为S_n，且a₂+a₃=6，则S₄的值为（　　）

A．12

B．11

C．10

D．9

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题型：填空题

完形填空。

     It was already late when we set out for the next town,   1   according to the map was about fifteen miles
away on the other side of the   2  . There we felt   3   that we would find a bed   4 the night. Darkness fell
soon after we left the village, but luckily we met   5   as we drove fast along the narrow winding road that
  6 the hills. As we climbed   7 , it became colder and rain began to fall,   8   it difficult at times to see the
road. I asked John, my companion, to drive more   9  .
    After we had traveled for about twenty miles, there was still no sign of the town which was  10  on the
map. We were beginning to get  11 . Then without warning the car stopped. A quick  12  showed that we
had run out of petrol (汽油). Although we had little food with us, we decided to  13  the night in the car.
     Our meal was soon over. I tried to go to sleep at once,  14  John, who was a  15  sleeper, got out of the
car after a few minutes and went for a walk  16  the hills. Soon he came back. From the top of the hill he
had seen, in the valley below, the  17  of the town we were looking for. We at once unloaded (卸) all our
luggage (行李) and with a great effort (努力),  18  to push the car to the top of the hill. Then we went back
to the luggage, loaded the car again and set off down the hill.  19 . less than a quarter of an hour we were in
the town, where we found a  20  quite easily.

( )1. A. which
( )2. A. rivers
( )3. A. surprised
( )4. A. at
( )5. A. everybody
( )6. A. got to
( )7. A. taller
( )8. A. getting
( )9. A. certainly
( )10. A. marked
( )11. A. excited
( )12. A. attention
( )13. A. spend
( )14. A. since
( )15. A. quick
( )16. A. across
( )17. A. lights
( )18. A. ought
( )19. A. For
( )20. A. policeman

B. it
B. hills
B. afraid
B. in
B. somebody
B. arrived
B. higher
B. thinking
B. carefully
B. set
B. worried
B. operation
B. live
B. though
B. fast
B. through
B. map
B. tried
B. In
B. friend

C. where
C. towns
C. pleased
C. through
C. nobody
C. led to
C. lower
C. causing
C. slowly
C. built
C. cold
C. examination
C. spare
C. so
C. poor
C. down
C. bus
C. succeeded
C. Since
C. hotel

D. that
D. villages
D. sure
D. for
D. anybody
D. belonged to
D. faster
D. making
D. surely
D. drawn
D. warm
D. information
D. stay
D. but
D. heavy
D. up
D. situation
D. managed
D. At
D. cinema

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题型：填空题

上猴车双手先握紧吊杆，（）脚站稳，（）脚先上。

A、右左

B、左右

C、无所谓

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题型：填空题

DIC分为以下3期（）、（）、（）。

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题型：填空题

煤矿窄轨铁路按国家标准轨距可分为三种类型：（）mm轨距；（）mm轨距；（）mm轨距。

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