安装完毕，再次检查钢结构要求（）。
A.结构安全正确
B.无变形
C.无开焊、裂痕
D.电动机正常
参考答案：A, B, C
—Can you guess ______ the new schoolbag yesterday?
—Sorry, I’ve no idea.
A．how much did he pay for
B．how much he spent
C．how much he paid for
D．how much did he spend
何谓调差系数？两台并联运行的发电机，为使无功负荷按机组容量分配，调差系数应有什么要求？
