You're late. ______? [ ]
A. Are you wrong
B. What's wrong
C. Is anything wrong
答案:B
已知集合A={a,2},集合B={a+1,5},若A∩B={2},则A∪B=
A.{1,2}
B.{1,5}
C.{2,5}
D.{1,2,5}
全面质量管理的基本要求是什么?