抛掷3枚质地均匀的硬币,A={既有正面向上又有反面向上},B={至多有一个反面向上},则A与B关系是( )
A:互斥事件
B:对立事件
C:相互独立事件
D:不相互独立事件
_________ Henry's mother ________ his father speaks English. They both speak Chinese.