为减少局麻药的吸收,常添加肾上腺素,浓度为()
A.1:200万
B.1:20万
C.1:2万
D.1:0.2万
E.1:50万
参考答案:B
Daniel insisted that it _____ his fault that the house was a mess and that he _____ sorry to his parents. [ ]
A. should not be…should not say
B. was not…should not say
C. was not… mustn't have said
D. should not be… didn't say
火力发电厂中常用的顺序控制项目有哪些?