《水质氯苯的测定气相色谱法》(HJ/T74--2001)规定,水中一氯苯用()溶剂萃取,()检测器测定。
参考答案:二硫化碳;氢火焰离子化(FID)
The normal ________ in this company is to send the bill as soon as the job is done.[ ]
A.practice
B.custom
C.habit
D.tradition
孕妇不宜针刺的腧穴有()。
A.三阴交
B.合谷
C.昆仑
D.至阴
E.曲池