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问题 选择题

图所示的四个实例中，目的是为了减小摩擦的是（　　）

A．

瓶盖上刻有纹线

B．

雪地行驶的汽车轮胎装有防滑链

C．

鞋底上制有花纹

D．

旅行箱下装有小轮

答案

A、瓶盖上刻有纹线，增大接触面粗糙程度来增大摩擦力．不符合题意．

B、雪地行驶的汽车轮胎装有防滑链，增大接触面粗糙程度来增大摩擦力．不符合题意．

C、鞋底上制有花纹，增大接触面粗糙程度来增大摩擦力．不符合题意．

D、旅行箱下装有小轮，用滚动代替滑动，减小摩擦力．符合题意．

故选D．

完形填空

Some countries are better than others at looking after the environment.In Europe,Germany（德国）and northem European countries work very hard to improve the environment.The people in Germany put their rubbish into different bags-paper in one bag,plastic in laws that do not allow people to burn too much coal. In the 1970s ,as people learned more about environmental problems,the “Green”movement（运动）began and soon spread all over Europe.The “Green ”movement tries to get governments to protect the environment.It collects information about how industry is damaging（毁坏）the environment and tells newspapers. 

小题1:Which countries in Europe work very hard to improve the environment? (within 5 words)

                                                                                          

小题2:Who put rubbish into different bags? (within 4 words)

                                                                                           

小题3:Can the people in Germany burn too much coal? (within 1 words)

                                                                                           

小题4:When did the “Green “movement begin? (within 3 words)

                                                                                           

小题5:What does the “Green”movement try to do?  (within 6 words)

                                                                                           
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填空题

城市道路建设中，人行道上都要求铺设供盲人行走的“盲道”，实现无障碍通行。如图是一幅人行道的照片，图片左侧是“盲道”，其地砖表面有一棱棱凸起的部分，而右侧是普通人行道，其地砖表面是平的。盲人行走时，如果不小心从盲道走到了普通人行道上，由于脚底与地面的接触面积     ，使脚底受到的压强       ，他能够根据脚底的感觉重新回到盲道上。  

 
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