搜题请搜索小程序“爱下问搜题”
问题 多选题
如图，两长方体木块A和B叠放在光滑水平面上，质量分别为m和M，A与B之间的最大静摩擦力为f，B与劲度系数为k的水平轻质弹簧连接构成弹簧振子．为使A和B在振动过程中不发生相对滑动，则（　　）
A．它们的最大加速度不能大于f/m
B．它们的最大加速度不能大于f/M
C.它们的振幅不能大于
D.它们的振幅不能大于
答案

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补全对话，情景问答

根据对话内容，在每小题的空白处填人适当的句子，使对话意思完整。

Samuel: Chen Li, can I have a look at your copy of China Daily?

Chen Li:    1   .

Samuel: I want to have a look at what's on this weekend.  Let me see now.

Chen Li: Is there anything good on?

Samuel:"Purple Rain Storm" is giving a performance at the People's Theatre.    2    ?

Chen Li: They're a pop group formed by three girls. They're said to be very good.    3   ?

Samuel: 7:30 pm.   4   .

Chen Li: Yes, I’ll be free. I'd like to go.

Samuel:    5    I'1l meet you at the theatre at 7:15.

ChenLi: Good! See you then. Bye.

1.                                                    

2.                                                

3.                                                

4.                                                

5.                                                
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连线题

连线题

将左右两部分相关的内容用线连起来。

a、缺维生素A              ①、脚气病

b、缺维生素B1             ②、夜盲症

c、缺维生素C              ③、佝偻病

d、缺维生素D              ④、坏血病
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