问题 填空题

著名的______实验证明了大气压强的存在.托里拆利在玻璃管内装入______较大的水银做实验测出大气压强的值,若换用水完成该实验,则需要______玻璃管的长度(选填“减小”或“增大”).

答案

(1)最早证明大气压存在的,并且最著名的实验是马德堡市的市长奥托格里克做的马德堡半球实验.

(2)首先测定大气压强值的是意大利物理学家托里拆利做的实验--托里拆利实验,他选用密度较大的水银进行实验,测出一个标准大气压能够支持0.76米高的水银柱,即一个标准大气压相当于0.76米高水银柱产生的压强,其大小为1.01×105Pa.

如果换用水来做,则玻璃管的长度至少为:

h=

P
ρg
=
1.01×105Pa
1.0×103kg/m3×9.8N/kg
=10.31m

因此需要增大玻璃管的长度.

故答案为:马德堡半球;密度;增大.

单项选择题 B型题
单项选择题

After winning a big game, athletes are often asked how they feel. Usually athletes say how (1) it is to win this big game. On the contrary, the fact is that losing a big game, or in my case, all the games, can be even harder.

From the spectators’ point of view, last year’s basketball (2) for my high school team was nothing (3) of an embarrassment. And (4) 0 and 20 is certainly nothing to be proud of, that season had a bigger impact on me than any other. As a team captain, I knew it probably wouldn’t be the (5) year, but did I ever think we would lose every game Of course not. Since six of our top players had graduated, it was clear that we were a (n) (6) team who would struggle. The struggle began earlier than expected, (7) , as our team center was suspended (禁赛) for the season, and two key members decided to (8) for some reason. At this point, dropping out probably passed through every player’s mind, but in the end, we all stuck if out, (9) to work still harder.

Then there came a time when even our (10) and given up on us. Personally, I felt like it was (11) worthwhile giving my all. I thought, if even the coach doesn’t believe in us, why should I But just as my hope began to (12) , a teammate called a meeting. He said," Nobody thinks we are going to win, but, as teammates and friends, we (13) it to each other to go all out every game. "

It was that moment that (14) me how to be a leader. It hit me that I certainly didn’t (15) the role. As a leader you can never quit (16) the team who looks up to you. It is one (17) to be named captain, feel great and go through the motions, but it is quite another to be a real captain and make sure everyone realizes their full (18) all the time.

I am sure it is great to go through without losing and bringing home awards. But in all honesty, I (19) the fact that my team lost every game last year. It may not help me to become a better basketball player, but it already has made me a better leader, and (20)

17().

A.matter

B.aspect

C.issue

D.thing