We arrived at the station ____ the train had left.
A.after
B.before
C.since
D.when
答案:A
试述实行股份制改组是大多数国有企业面向市场经济体制的必由之路。
痛风石可存在于()
A.关节
B.皮肤
C.肺脏
D.关节软骨
E.肌建