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问题 选择题

下列事例中，属于热传递改变内能的是

A．夏天，柏油马路在烈日下会被晒热

B．冬天，两手相互搓一搓就会暖和

C．流星在大气层中穿行会发光发热

D．用打气筒给轮胎打气，筒壁会发热

答案

答案：A

A、柏油路在太阳的照射下温度升高，是因为太阳光的温度高于路面，从而通过热传递增加了柏油路的内能；故A正确；

B、搓手时感到暖和是因为手克服摩擦力做功，将机械能转化为内能，故B错误；

C、流星在大气层中由于受到摩擦力，从而消耗机械能转化为内能，故C错误；

D、给自行车打气时，活塞压缩气体做功，机械能会转化为气体的内能，即通过做功的方式改变物体的内能，故D错误；

故选A．

单项选择题

男，63岁，既往有高血压、冠心病及胃溃疡，1天前突然剧烈上腹部刺痛、濒死感伴发热。白细胞增多，心电图Ⅱ、Ⅲ、aVF、ST段抬高，有病理性 Q波，诊断为

A．心绞痛
B．急性心包炎
C．急性肺动脉栓塞
D．急性心肌梗死
E．急腹症
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完形填空
完形填空。

     The first time I remember noticing the crossing guard was when he waved to me as I drove
my son to school.He__1__me with a puzzle-all because he waved to me like someone does
__2__ seeing a close friend.A big,__3__smile accompanied his wave.For the next few days
I tried to__4__his face to see if I knew him.I didn't.Perhaps he had__5__me for someone else.
By the time I contented myself with the__6__that he and I were strangers,we were greeting
each other warmly every morning like old friends.
     Then one day the__7__was solved.As I__8__the school he was standing in the middle of
the road__9__his stop sign.I was in line behind four cars.__10__the kids had reached the safety
of the sidewalk,he lowered his sign and let the cars__11__.To the first he waved and__12__in
just the same way he had done to me over the last few days.The kids already had the window
down and were happily waving their reply.The second car got the same__13__from the crossing
guard,and the driver,a stiff looking(表情刻板的)businessman,gave a brief,almost__14__wave
back.Each following car of kids on their way to school__15__more heartily.
     Every morning I continued to watch the man with__16__.So far I haven't seen anyone__17__
to wave back.I find it interesting that one person can make such a(n)__18__to so many people's
lives by doing one simple thing like waving and smiling warmly.His__19__armed the start of my
day.With a friendly wave and smiling face he had changed the__20__of the whole
neighbourhood.

( )1.A.hit
( )2.A.on
( )3.A.false
( )4.A.research
( )5.A.praised
( )6.A.conclusion
( )7.A.argument
( )8.A.visited
( )9.A.drawingback
( )10.A.Once
( )11.A.in
( )12.A.cried
( )13.A.idea
( )14.A.awkward
( )15.A.came
( )16.A.surprise
( )17.A.fail
( )18.A.offer
( )19.A.effectiveness
( )20.A.trends 		B.disappointed
B.from
B.shy
Bstudy
B.blamed
B.description
B.disagreement
B.approached
B.puttingon
B.Before
B.through
B.cheered
B.reply
B.angry
B.responded
B.frustration
B.try
B.sacrifice
B.cheerfulness
B.observations 		C.presented
C.during
C.apologetic
C.recognize
C.mistaken
C.evaluation
C.mystery
C.passed
C.handingin
C.Unless
C.out
C.smiled
C.notice
C.elegant
C.hurried
C.interest
C.wish
C.promise
C.carefulness
C.regulations 		D.bored
D.about
D.bright
D.explore.
D.respected
D.introduction
D.task
D.left
D.holdingout
D.While
D.down
D.gestured
D.greeting
D.patient
D.appeared
D.doubt
D.bother
D.difference
D.seriousness
D.feelings  
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