What's the relationship(关系) between the two speakers?
A:Doctor and patient(病人).
B:Teacher and student.
C:Boss and clerk.
下列有关木本植物茎的说法中,错误的是( )
阅读下表(表中之数字,表示各时代在各区域中治水事业活动之次数)。据此无法推论的是( )