小球从空中自由下落，与水平地面相碰后弹到空中某一高度，其速度随时间变化的关系如图

发布时间：2017-05-20 14:49 │ 来源：www.tikuol.com

题型：选择题

问题：

小球从空中自由下落，与水平地面相碰后弹到空中某一高度，其速度随时间变化的关系如图所示，g取10m/s²，则

A．0.8s内小球的位移为零

B．0.8s内小球的路程为1.7m

C．0～0.5s与0.5s～0.8s物体的加速度方向相反

D．小球能弹起的最大高度为0.45m

考点：其他运动图像

题型：选择题

完形填空：通读下列短文，从每题所给的四个选项A、B、C、D中，选出可以填入空白处的最佳选项。

    One night, Mary heard some big   1 noise. "Doh, Doh, …" It   2 for a few minutes. Mary went out of her
bedroom to search everywhere. Her parents were sleeping and there were no   3 people in the house. Mary
returned to her bedroom.
    Mary heard   4 again. She thought, "Is it a cat? Mike has a cat. But cats miaow. They don't make such
noise."
    "Maybe it's a bird   5 around and looking for a place to rest. No! That doesn't make any noise."
    "Maybe it's the whisper of my parents. They   6 be   7 in their room. But that noise wasn't a whisper at all."
     Mary went to bed again but she heard the noise again. She was   8 and fell   9 her bed. Her legs were 10
and she could not climb up any more.

( ) 1. A. strongly
( ) 2. A. sounded
( ) 3. A. any
( ) 4. A. the noise
( ) 5. A. going
( ) 6. A. should
( ) 7. A. sleep
( ) 8. A. frightening
( ) 9. A. down
( ) 10. A. weak

B. strange
B. went about
B. other
B. a noise
B. flying
B. may not
B. talking
B. frightened
B. from
B. strong

C. frightened
C. went on
C. the other
C. noise
C. jumping
C. must
C. talk
C. amazed
C. off
C. sick

D. loud
D. went away
D. others
D. noisy
D. running
D. mustn't
D. sleeping
D. amazing
D. in
D. ill

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题型：选择题

三角形的其中两条边为8跟9，那么三角形的第三边不能为（　　）

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题型：选择题

我国新一轮出口退税率调低的主要影响对象是( )。

A．三资企业和民营企业
B．三资企业和国营企业
C．个体企业和民营企业
D．联营企业和私营企业

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题型：选择题

上山开口，临时安在坡底的倒拉车，必须安在弯道的外侧，小绞车最突出部位（包括点柱）距上山临近直道延长线（）mm以上（附图二），其它要求执行第12条。

A、600

B、700

C、800

D、900

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题型：选择题

成本定价法中，价格是由（）几个部分组成。

A、成本

B、利润

C、税收

D、费用

E、市场

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