中度有机磷杀虫药中毒时全血胆碱酯酶活性为()
A.90%~70%
B.70%~50%
C.50%~30%
D.30%~l0%
E.以上均不确切
参考答案:C
She is very dear to us.We have been prepared to do ________ it takes to save her life.
A.whichever
B.however
C.whatever
D.whoever
机组运行时漏油泵频繁起动,说明()。
A、调速系统用油量大
B、导叶开关次数多
C、接力器漏油量大