额定电压35~63kV断路器接线端子允许的水平机械荷载为()。
A.150
B.250
C.500
D.750
参考答案:C
—Shall I use your red ink?
—It's a pity that it ______. I will get some.[ ]
A. has run out
B. has used up
C. has run out of
D. has been run out
水溶性维生素的体内营养状况鉴定可通过()试验来进行。