消防应急照明和疏散指示系统的定期应急放电时间不能低于()min,否则需要更换产品。
A.20
B.30
C.60
D.90
参考答案:B
The price of this kind of computer varies from 3,000 yuan, to 10,000 yuan, the brand(品牌). [ ]
A. depending on
B. concentrating on
C. working on
D. going on
能使磷酰化胆碱酯酶复活的药物是()
A.阿托品
B.氯解磷定
C.毛果芸香碱
D.毒扁豆碱
E.新斯的明