设A,B,C为三个随机事件 ,且P(A)=P(B)=P(C)=1/4,P(AB)=0,P(AC)=P(BC)=1/12,则A,B,C中恰有一个事件发生的概率为()
A、3/4D
设矩阵
，则（）
he teacher told them since light ________ (travel) faster than sound,lightning ________ (appear) to go before thunder.
Wood does not conduct electricity; ________.
党的过渡时期总路线所指的过渡时期是 _________。
The opposition leaders ________ the government for not taking action sooner.
