实验室制取气体选择收集方法时，下列性质：①颜色；②密度；③溶_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题选择题

实验室制取气体选择收集方法时，下列性质：①颜色；②密度；③溶解性；④可燃性；⑤能否与水反应，必须考虑的是[ ]

A ．①②③

B ．②③④

C ．③④⑤

D ．②③⑤

答案

答案：D

选择题

— Excuse me, sir. Would you do me a favour?
— Of course. What is it?
— I _____ if you could tell me how to fill out this form.

A. had wondered
B. was wondering
C. would wonder
D. did wonder

问答题简答题

经营（销售）医疗器械产品需具备什么资格？