A.乙不带电
B.乙带负电
C.乙带正电
D.无法判断
答案:B
I play ____________ basketball at 4: 00. And I play ____________ piano at 7: 00.[ ]
A. the; the
B. /; the
C. the; /
周转时间=全炉操作时间+()。