问题 选择题

做功和热传递是改变物体内能的两种方式.下列方法中,属于做功改变物体内能的是(  )

A.炉火上的壶水逐渐升温的过程

B.柴油机气缸内气体被压缩的过程

C.物体在阳光下被晒热的过程

D.把烧红的铁块投入水中使铁块温度降低的过程

答案

A、炉火上壶水升温是因为炉火的温度高于水的温度,从而发生了热传递;故A错误;

B、柴油机气缸内的气体被压缩,故压缩机对气体做功,气体增加内能,故正确;

C、物体在阳光下晒热是因为物体吸引了太阳的热量,故属于热传递,故C错误;

D、铁块放入水中时,由于铁块的温度高于水的温度,发生了热传递现象,故D错误;

故选B.

完形填空
Youth sports teach kids to develop a winning state of mind as well as the ability to become team leaders. Although having   __  is a major part of athletics, the only purpose of sports is to compete and create the   ____  mentality (心态) people need in sports.
____  have the extremely hard task of getting their young athletes to learn how to play the sport and become disciplined, and ready to play the sport to the best of their ability.   ____, I was at my younger brother's baseball game the other night and his team was   ____ by five runs in the last part of the game. While most teams in this situation would be desperately trying to regain their  ____   for bravery and will to fight, his team just seemed to slowly walk around,    ____  sunflower seeds, and laugh at jokes made by teammates. I asked my brother after the game why everybody was so   ___  about the loss and he said it was because some kid's mom brought really good snacks.
Some parents have a  ___  with coaches shouting at their child, as they hold the view that if  a child makes a mistake, it is the coach's   ___   to correct the problem. When parents get  involved in telling the coach how to   __11__  the team, problems  ____. Some parents feel if they  pay their money, they should have an equal  ___  on how to coach the team. In order to have a  successful learning experience, the coach needs to feel like he can control his team and  ____  the  parents from having the last say. Without that, the coach feels as if he needs to   ____   the  parents by giving more playing time to their kids who actually don't  ____  it.
With youth sport programs becoming less competitive, club teams are on the  ____. More  teens can get an easier access to them. Club teams   ____  more of what high school and junior  high coaches are looking for, the competitive edge that is absolutely necessary in   ____. While  having fun is important, skills and a   ____  mentality is worth more in the world of sports.
小题1:
A.funB.dignity
C.courageD.patience
小题2:
A.socialB.competitive
C.healthyD.responsible
小题3:
A.CoachesB.Parents
C.ExpertsD.Headmasters
小题4:
A.As a resultB.In addition
C.For exampleD.On the contrary
小题5:
A.upB.below
C.aboveD.down
小题6:
A.scoresB.goals
C.spiritsD.dreams
小题7:
A.chewB.spit
C.countD.swallow
小题8:
A.worriedB.happy
C.seriousD.casual
小题9:
A.jokeB.problem
C.contactD.compromise
小题10:
A.dutyB.experience
C.awarenessD.turn
小题11:
A.dismissB.unite
C.handleD.assess
小题12:
A.stand outB.break out
C.work outD.come out
小题13:
A.sayB.guidance
C.responseD.reward
小题14:
A.protectB.defend
C.excuseD.discourage
小题15:
A.assistB.motivate
C.pleaseD.blame
小题16:
A.wantB.deserve
C.valueD.appreciate
小题17:
A.wayB.decline
C.goD.rise
小题18:
A.offerB.require
C.seekD.preserve
小题19:
A.academicsB.sports
C.examsD.competitions
小题20:
A.riskingB.controlling
C.winningD.cooperating
单项选择题 共用题干题