题目

已知两个有理数a,b，如果ab<0,a+b<0,那么（ ） A . a>0,b<0 B . a<0,b>0 C . a,b异号 D . a,b异号且负数的绝对值较大 答案：D一There's a sign "Be quiet" on the wall of the reading room.一Yes. People talk loudly in public.A. may not B. mustn't C. can't D. needn't