易于挥发（逸散）的药品是
A．氢氧化钠
B．碘酊
C．碘化钾
D．乙酰水杨酸
E．氯化铵
参考答案：B
Mary _______ her mother with the housework, but she didn’t.
A．must have helped
B．ought to have helped
C．must help
D．should help
A．5A
B．5A
C．5/2A
D．/2A
A
/2
/2A