使用 滑轮不能省力，但可以改变 ；使用 滑轮可以省一半力．就杠杆的力臂长短关系来
题型：填空题
问题：
使用 滑轮不能省力，但可以改变 ；使用 滑轮可以省一半力．就杠杆的力臂长短关系来看，定滑轮实际上就是 杠杆，而动滑轮是 的杠杆．
题型：填空题
第二节 完形填空（共20小题，每小题1.5分，共30分）
阅读下面短文，掌握其大意，从每题所给的A、B、C、D四个选项中，选出最佳选项并在答题卡上将该项涂黑。
More good things come from small things
About a year ago, a couple with three children moved into the apartment next door to me.
I never heard any 36 from the children, but the parents were always shouting at the kids.
We 37 often in the hallways when we were coming or going. I 38 spoke, but the only 39 I ever got was a hello from the four – year – old girl.
I usually go out for breakfast and one day when I 40 they were just coming from their apartment and the little girl was holding the door 41 for the others. I 42 in the car doing unnecessary things because I didn’t like to be snubbed（冷落）. The parents were 43 her to hurry and get in the car, I looked up and saw the little girl was 44 holding the door open, 45 for me.
I hurried as much as I could and 46 her. She was smiling from ear to ear. That afternoon I saw a white toy bear, I 47 the little girl and said to myself, “I 48 she would like that” so I bought it. I wrote a note 49 how much her act of kindness had touched a soft spot in an old man’s 50 .
The next day there was a 51 on the door and 52 was the little girl and her father. She was so proud of her bear and thanked me. Then I 53 her mother and the other children were there in the hall too. The mother and father both thanked me.
Now when we meet in the hall we all speak, and in a 54 manner, I might add. 55 time
passes, I don’t hear that shouting as often. In fact, hardly at all.
36．A．sound B．noise C．conversation D．crying
37．A．met B．saw C．visited D．gathered
38．A．never B．sometimes C．seldom D．always
39．A．reward B．action C．answer D．prize
40．A．moved B．returned C．started D．drove
41．A．open B．closed C．fit D．active
42．A．stopped B．kept C．worked D．remained
43．A．suggesting B．telling C．forcing D．making
44．A．ever B．even C．still D．yet
45．A．waiting B．calling C．leaving D．asking
46．A． replaced B．encouraged C．ignored D．thanked
47．A．thought about B．thought of C．thought over D．thought out
48．A．decide B．am lucky C．am sure D．doubt
49．A．saying B．statin
g C．reporting D．writing
50．A．mind B．body C．thought D．heart
51．A．hit B．knock C．drop D．beat
52．A．she B．it C．they D．he
53．A．noticed B．watched C．recognized D．felt
54．A．kindly B．politely C．coldly D．friendly
55．A．When B．Since C．As D．While
已被氧化（简述实验步骤）：