主、辅吊车对设备的运动速度之间的关系是（）。A、当设备仰角小_爱下问搜题

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问题多项选择题

主、辅吊车对设备的运动速度之间的关系是（）。

A、当设备仰角小于45°时，送尾速度小于起升速度

B、当设备仰角等于45°时，送尾速度等于起升速度

C、当设备仰角大于45°时，送尾速度等于起升速度

D、当设备仰角大于45°时，送尾速度大于起升速度

答案

参考答案：A, B, D

改错题

     Cell phones can be see almost everywhere at

school now. Many teacher say that we students

should not used cell phones at school. But I think

it should be allowed to be used at school because

we want to get touch with our parents. Cell

phones can be used almost anywhere or at any

time. What more, cell phones can be great fun,

too. Besides make phone calls, we can also play

games and sent text messages to our friends by

cell phone. Don't you think of they are necessary?

1._____

2._____

3._____

4._____

5._____

6._____

7._____

8._____

9._____

10._____

填空题

镀锡原板用钢大多采用低碳钢，其含碳量一般为（）。