单选题 The meeting is postponed until next week, ______ we won't be so busy.
  • A) since
  • B) when
  • C) while
  • D) that


【正确答案】 B
【答案解析】[解析] when引导非限制性定语从句，对先行词next week起补充说明作用。当定语从句的先行词是表示时间的名词时，关系副词常用when，相当于during which。