三相异步电动机在电动状态下运行时，其转差率S约为（）。
A.n=0；s=1
B.0＜S＜1
C.0.004～0.007
D.0.04～0.07
参考答案：B
She had wanted to go to the west part of China in search of better view. But she turned ___voluntary teacher there.
A．a; /
B．the; /
C．the; a
D．a; the
618÷7商是______位数，250×8积的末尾有______个0．
小明今年l0岁，爷爷的年龄是他的6倍多4岁，爷爷今年______岁．
