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问题 选择题

如图所示，一个物块在与水平方向成角的恒定推力F的作用下，沿水平面向右运动一段距离。在此过程中，恒力F对物块所做的功为（  ）

A．

B．

C．

D．

答案

答案：C

本题考查的是恒力做功问题，力F与位移方向的夹角为，则恒力F对物块所做的功为   ，C正确；ABD错误；

问答题

按要求完成下列各题。

1. Sam: How about trying the new French restaurant tonight?

   Tom: I heard it's very expensive. 

   Sam: Why don't we go Dutch? 

   Tom: Good idea!

    Read the dialogue, can you guess the meaning of "go Dutch"? You may answer it in Chinese. 

                                                                                                                                        

2. Sue is 5 years older than her younger brother Paul. Paul is 6 years older than Jim, the youngest in the family.

    If the total of the children's ages is 32, how old is the eldest child? 

                                                                                                                                         

3. What number should replace the question mark in the last circle? 

      

                                                                                                                                           

4. Which letter should appear in the final medal?

                                          

                                                                                                                                            

5. Look at the shapes and codes given. Work out the code which matches the shape given at the end of the line.

      

                                                                                                                                              

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单项选择题

对北京时间的叙述，不正确的是（）

A.东八区的区时

B.东八区中央经线的地方时

C.东经120°的地方时

D.北京市的地方时
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