Question

19. You can't complain about being left out    you don't make any effort to share

your joys and sorrows with others.

A. once      B. unless

C. when     D. though

Answer 1

19.   C考査状语从句的连接词。句意：既然你都不努力去和别人分享你的快乐和悲伤，你就不能抱怨被人冷落。once —旦，曾经；unless除非；when当.....时候，既然；though虽然。根据句意可知选C。