题目

甲、乙两人进行乒乓球比赛，比赛采取五局三胜制，无论哪一方先胜三局则比赛结束，假定甲每局比赛获胜的概率均为，则甲以3∶1的比分获胜的概率为( )A. B. C. D. 答案：【答案】A【解析】试题分析：前3局有2局甲获胜，最后一局甲胜，故3:1获胜的概率是,故选A.Every day I spend two hours my homework.A. finishing to do B. finishing doingC. to finish doing D. to finish to do