题目

已知a，b，c，d为实数，且c＞d．则“a＞b”是“a﹣c＞b﹣d”的（  ） A . 充分而不必要条件 B . 必要而不充分条件 C . 充要条件 D . 既不充分也不必要条件 答案：B(2013·皖南八校模拟)The band was very successful in the seventies, most of　　　members were in their twenties. A．itsB．whoseC．whom D．which