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问题 选择题

下列事例中，属于增大压强的是（　　）

A．在螺钉下加一个大垫圈

B．图钉帽的面积都做得较大

C．切蛋器装有很细的钢片

D．用薄纸片垫在塑料袋提手处

答案

ABD选项中，都是在压力一定情况下，通过增大受力面积的方式来减小压强，故不符合题意．

C选项，是在压力一定情况下，通过减小受力面积来加大压强．

故选C．

选择题

读“某地等高线（米）地形示意图”，完成1~3题。

1．某地高出另一地的垂直距离叫做相对高度。图中A山峰海拔为270米，A山峰与B地的相对高度可能为  [ ]

A．50米          

B．40米    

C．30米          

D．20米

2．下列四条登山线路中，坡度最缓的是  [ ]

A．AB线                      

B．AC线    

C．AD线                      

D．AE线

3．若该图比例尺为1：6000000的地图上，小明在图上量AC两地直线距离为3厘米。经计算，两地之间的实际直线距离应是[ ]

A．1．8千米  

B．18千米  

C．180千米

D．1800千米
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单项选择题

Randy Kraus was paralyzed. His left side was useless. But his right hand was (1) enough to lift a bucket to his forehead. Once, he’d been a police officer and owned a private-eye agency. Once, he’d been p and able. Now, he felt he was nothing.
His (2) started with Parkinson’s disease, but it didn’t (3) there. In July 2002, the 60 year old Kraus went into the hospital for an operation to control the shaking. (4) , during the operation, he had a stroke. He was paralyzed. The (5) man, who loved golf, could think, but couldn’t (6) . Kraus wanted the doctors to (7) it to him straight. "You may never walk again, " they told him. "Maybe you won’t (8) be able to talk. "
Once at home, he (9) he couldn’t lift a fork or take a drink by himself. Physical treatment was so painful and slow. What did he have to (10) for So now Kraus held the gun against his head. (11) the cold metal on his skin, he began to consider not his pain, but the pain he (12) cause his wife, daughters and grandchildren. He didn’t pull the trigger.
"You are where you are", his exercise physiologist, Andrew Garud told him. "The pace would be slow; the pain would be (13) . But as long as you are (14) , you have the ability to get better. " After three months of (15) with Garud, Kraus wanted to see if he could (16) . He could. Then he took three steps, sat down and cried like a baby. One step (17) to another. Next he managed a short walk. It was the hardest (18) of Kraus’s life.
Garud kept saying he could (19) more. Now, Kraus can brush his teeth, shave himself and get around the house with a walker. Little success only the paralyzed can (20) understand.

A．search
B．try
C．live
D．look
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