齿轮泵的大修周期为()。
A.6个月
B.12个月
C.24个月
D.36个月
参考答案:C
--Do you want a lift home?
---It’s very kind of you, but I have a much late in the office. I overslept this morning because my morning clock _______.
A.doesn’t go off
B.won’t gone
C.wasn’t going off
D.didn’t go on
导线越长,电阻越大,电导也就越大。