1140V低压电网的漏电动作电阻值为()M
A.40
B.30
C.20
参考答案:C
—_____ your friend from the USA?
—No, he's an English boy. [ ]
A. Do
B. Does
C. Is
D. Are
阻聚剂的作用过程是()。
A、分离
B、吸收
C、分散
D、吸附