新载玻片常带有游离碱质,清洗必须用
A.1mol/L酒精
B.1mol/L HCl
C.1mol/L乙醚
D.1mol/lNaOH
E.1mol/LNaHCO3
参考答案:B
影响土坝坝坡的因素有哪些?如何影响?
Jack admitted that he ought not to have made his mother angry, ______A. oughtn’t he B. wasn’t heC. didn’t heD. hadn’t he