the book was written in 1946,-----the education system has saw great changes.
问题描述:
the book was written in 1946,-----the education system has saw great changes.
答案用since when 为什么不用since which 代since 1946 ?since 是介词定语从句中不是要介词加关系代词的吗
答
因为就像你说的一样是since1946,而which是不能指代时间,它可以指代某个人或某样东西但不能指代时间,而1946是个时间,能表示时间的只能是when所以用sincewhen