气球以10m/s的速度匀速上升,当它上升到离地15米高处,从气球上掉下一个物体,

题型:填空题

问题:

气球以10m/s的速度匀速上升,当它上升到离地15米高处,从气球上掉下一个物体,不计空气阻力则物体落地时的速度为____________。

考点:机械能守恒定律
题型:填空题

将一张长方形纸片只折一次,使得折痕平分这个长方形的面积,这样的折纸方法共有[ ]

A.2种

B.4种

C.6种

D.无数种

题型:填空题
A man who knows how to write a personal letter has a very powerful tool. A letter can be enjoyed, read and   36 . It can set up a warm conversation between two people far apart (远离的);it can keep a   37  with very little effort.
I will give   38 .A few years ago my older brother and l were not getting   39 .We had been close as    40   but had grown apart. Our meetings were not   41 ; our conversation was filled with arguments and quarrels: and every effort to clear the air seemed to only   42  our misunderstanding. Then he   43  a small island in the Caribbean and we   44  touch. One day he wrote me a letter. He described his island and its people, told me what he was doing, said how he felt, and encouraged me to   45 . Rereading the letter, I was   46  by its humor(幽默)and clever expressions. These were all qualities for which I had   47  respected my older brother but   48  he no longer had them. I had never known he could write so  49  . And with that one letter we became friends   50 .
It might never have occurred to   51  to write me if he had not been in a place where there were no   52 . For him, writing was a necessity. It also turned out to be the best way for us to get back in touch. Because we live in an age of  53  communication(通讯), people often   54  that they don’t always have to phone or email. They have a  55  . And that is to write.
小题1:
A.receivedB.rewrittenC.returnedD.reread
小题2:
A.recordB.promiseC.friendshipD.secret
小题3:
A.an exampleB.a lessonC.an experienceD.a talk
小题4:
A.throughB.togetherC.alongD.away
小题5:
A.brothersB.childrenC.fellowsD.classmates
小题6:
A.normalB.necessaryC.pleasantD.possible
小题7:
A.deepenB.startC.expressD.settle
小题8:
A.touredB.stopped C.reachedD.moved to
小题9:
A.lostB.kept inC.neededD.got in
小题10:
A.thinkB.writeC.enjoyD.read
小题11:
A.drivenB.beatenC.surprisedD.honored
小题12:
A.neverB.seldomC.sometimesD.once
小题13:
A.realized B.judgedC.thoughtD.expected
小题14:
A.wellB.oftenC.muchD.soon
小题15:
A.laterB.anyhow C.tooD.again
小题16:
A.us B.anyoneC.someoneD.my brother
小题17:
A.mail servicesB.transport servicesC.phonesD.relative
小题18:
A.poor B.easy C.popularD.busy
小题19:
A.believeB.decideC.argueD.forget
小题20:
A. habitB.choiceC.methodD.plan
题型:填空题

利多卡因(含肾上腺素)行局部浸润麻醉,作用时间最长可达()

A.80min

B.100min

C.120min

D.240min

E.360min

题型:填空题

在国际工程承包合同中,下列不属于采用DAB(争端裁决委员会)方式解决争端的优点的是()。

A.DAB委员由行政主管部门指派,裁决具有公正性.中立性

B.DAB委员可以在项目开始时就介入,了解项目管理情况及存在的问题

C.DAB解决纠纷的周期较短

D.DAB的费用较低

题型:填空题

甲、乙两图分别表示光照强度和空气中CO2浓度对某绿色植物光合作用的影响,其中S1S2S3的面积大小表示有关生理过程产生或消耗有机物的量。丙图示探究叶片光合作用速率的装置。请据图回答以下问题:

在甲图中,呼吸作用消耗有机物的量可表示为(),光合作用产生有机物的量可表示为()(用S1S2S3和数学符号)。写出与呼吸作用有关的反应式(底物为C6H12O6

更多题库