真空断路器的行程为()。
A.30mm
B.20mm
C.10mm
D.8mm
参考答案:C
The pay is not good, but people usually find social work _____ in other ways.
A.payable
B.respectful
C.interested
D.rewarding
己内酰胺萃取中()为连续相。
A、苯
B、硫铵
C、粗油
D、水