施工作业过程中如要进行动火作业,必须办理()。
参考答案:动火令
If x is an even integer and y is an odd integer, then which of the following is an even integer ?()
A.x2+y
B.x2-y
C.(x2)(y)
D.x+y
E.x-y
如何克服控制系统的滞后?