―The Chengdu city is taking on a new look every day.―So it is.But more traffic signs in English should be________in the streets for the convenience of the foreign tourists.A.made up B.built up C.taken up D.put up 答案:D 甲乙独立解同一个问题,甲解决这个问题的概率是 ,乙解决这个问题的概率为,那么恰好有一人解决这个问题的概率为 ( )
A.
B.(1-)+ (1-)
C.1-
D.1-(1-)(1-)