题干
I will take my parents to the museum ________ it doesn't rain this afternoon.
A：or
B：if
C：so
D：and
答案(点此获取答案解析）
B
I will take my parents to the museum ________ it doesn't rain this afternoon.
A：or
B：if
C：so
D：and
－NMR（核磁共振）可用于含碳化合物的结构分析，
( )