步进电动机的连续运行频率应大于起动频率
参考答案：对
— When did it begin to snow?
— It started _____ the night.[ ]
A. during
B. by
C. in
D. at
执行下面的程序段后，变量S的值为( )。 S=5 For i=2.6 To 4.9 Step 0.6 S=S+1 Next i
A．10
B．8
C．9
D．7
