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

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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
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根据《执业药师资格制度暂行规定》,执业药师资格考试合格者取得的《执业药师资格证书》

A.在全国范围内有效

B.在证书颁发的省内范围有效

C.在取得者长期居住所在的省内有效

D.在取得者执业所在的省内范围有效

E.在取得者的身份证发放的省内范围有效

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一患者因黄染一周就诊。超声示肝脏肿大,回声增强,肝内胆管树枝状扩张,肝外胆管未显示,胆囊未充盈,其梗阻部位最可能为()。

A.胆总管十二指肠后段

B.胆总管壶腹部

C.胆总管胰腺段

D.肝门部

E.胆总管十二指肠上段

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Do you suppose Darwin, one of the greatest scientists of all time, really did foolsexperiments? Or did he do experiments that were so simple and basic that other people just thought they were foolish?

  Sometimes, people think they already know the answer to a question or the solution (解决办法) to a problem. Sometimes, they really do know an answer or a solution, but without thinking they are important.

  Charles Darwin didn’t settle for (满足于) just thinking he knew something. And, he believed all things could be important however simple they seemed to be.

  Suppose you drop sheets of paper that are of exactly the same size and shape. If you drop them at the same time in the same place, they will fall in the same way. Now make one of the sheets of paper into a tight (紧的) little ball and let it drop along with the other sheets. What happens? You have done an experiment that is so simple that you might think it couldn’t be worth anything.

  But this simple experiment is important. It explains part of our present-day understandings of physics, ideas that were worked out long ago by Galileo and Newton. And these understandings set aside some of ancient Greek physics.

Scientist sometimes stops to look at very simple things and to think very hard about them. Even the simplest idea, which we might think is foolish, can shake the foundations of science.

1. 小题1:The passage tells us that Charles Darwin ____.

A.was a great English scientist

B.always liked doing the experiments that others thought difficult

C.thought even the simplest thing was important

D.didn’t get well with others2.小题2:The phrase “set aside” most probably means____ .

A.throw away

B.store up

C.put to use

D.realize3. 小题3:The author of the passage tries to ________.

A.convince us that Charles Darwin, Galileo and Newton are the greatest scientists in the world

B.draw the conclusion that basic sciences are simple things

C.prove that two sheets of paper, with the same size and shape, will fall at the same speed

D.draw our attention to everyday happenings around us4小题4:Which of the following is TRUE?

A.Darwin really did fools experiments.

B.According to some people Darwin did foolish experiments.

C.It is believed by all the people that things could be important though they seemed to be simple.

D.Galileo and Newton worked out ancient Greek physics.

题型:选择题

测定水中余氯时,最好在现场分析,如果做不到现场分析,需在现场用过量NA.OH固定,且保存时间不应超过()不时。

A.6

B.24

C.48

题型:选择题

弘扬主旋律和提倡多样化是难以调和的矛盾。这个观点正确吗?

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