小明同学利用圆珠笔杆、钢丝、细绳制成了如图所示的滑轮组用其匀速提升重物,不考虑摩

题型:选择题

问题:

小明同学利用圆珠笔杆、钢丝、细绳制成了如图所示的滑轮组用其匀速提升重物,不考虑摩擦、笔杆和绳重,下列说法正确的是(  )

A.拉细绳的力F等于钩码重力G的

B.拉细绳的力F等于钩码重力G的

C.拉细绳的力F等于钩码重力G的

D.拉细绳下降的距离是钩码上升高度的

考点:滑轮组及其工作特点滑轮(组)中拉力的计算
题型:选择题
Denny Crook was a famous photographer(摄影师). He traveled all over the world, taking pictures for magazines and newspapers, and won many prizes.
“I’ll do anything to get a good photo,” he often said. “I’ll go anywhere at any time, even if it is
   41  .”
And he told the     42  .He had photos of earthquakes, forest fires, floods and even wars. If something interesting happened, Denny went to photo it.
He was a married man and his wife often asked him to take her with him, but he always    43  . “I’ll travel for my work, not for    44  ,” he told her. “You won’t enjoy yourself, and I won’t have    45  to look after you. Sometimes there’s not even anywhere to     46  ,and I have to sleep outside. I often don’t have a good     47   or a bath for days. You won’t like it.”
“Denny, I’m not a child,” his wife didn’t     48   . “I can look after myself. Please take me with you the next time you go overseas.”
Denny did not say anything, but he     49   about it, and when he was asked to go to Africa he said to his wife,” You can come to Africa with me if you want to. I’ve got to take photos of wild   50  there. It should be interesting and not too uncomfortable.”
His wife was very     51  ,and at first she had a very enjoyable time.
Then Denny went off to     52  some lions to photo. His wife went with him, but before long they became separated(分开).She walked down one path while he walked down the other.
Suddenly, Denny heard her     53   .He ran back and saw her running toward him. A huge lion was chasing her.
Quickly Denny took his camera out of its case and     54   it at his wife and the lion.
Then he shouted, “    55  ,woman !I can’t get you both in the picture!”
小题1:
A.dangerousB.naturalC.convenientD.impossible
小题2:
A.lieB.reasonC.newsD.truth
小题3:
A.allowedB.refusedC.failedD.joked
小题4:
A.wealthB.prizeC.pleasureD.luck
小题5:
A.moneyB.timeC.interestD.ability
小题6:
A.meetB.workC.shopD.stay
小题7:
A.mealB.picnicC.roomD.party
小题8:
A.agreeB.understandC.replayD.complain
小题9:
A.worriedB.forgotC.askedD.thought
小题10:
A.landB.flowersC.animalsD.people
小题11:
A.exciting B.excitedC.surprisedD.surprising
小题12:
A.findB.feedC.driveD.shoot
小题13:
A.singingB.cryingC.laughingD.cheering
小题14:
A.threwB.firedC.showedD.pointed
小题15:
A.Hurry upB.Look outC.Slow downD.Go ahead
题型:选择题

机动车道的宽度取决于通行车辆的车身宽度和车辆行驶中横向的必要安全距离。根据一般经验,城市道路机动车辆横向安全距离可取()m。

A.0.1~0.5

B.0.6~1.0

C.1.0~1.4

D.1.5~1.9

题型:选择题

胸部外伤后开胸探查手术的指征是()

A.胸内异物

B.膈肌破裂

C.气管支气管损伤

D.胸内持续出血

E.以上都是

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我国最大的盐场是位于______海的________盐场。

题型:选择题

伤亡事故经济损失的评价指标包括( )。

A.死亡人数和百万元产值经济损失率
B.千人经济损失率和百万元产值经济损失率
C.死亡人数和千人经济损失率
D.工作损失价值和死亡人数

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