—When did your father come back last night?

—He didn't come back _____ he finished all the work. [ ]

A. until

B. while

C. if

社会主义商品经济的作用有______。

A．提高劳动生产率，推动生产迅速发展

B．促进资源优化配置，加快实现现代化

C．增强企业活力

D．促进社会公平

E．增加社会产品，满足人民需要