What they discussed is ___________they should build the library next year.
问题描述:
What they discussed is ___________they should build the library next year.
A.that when B.that where
C.where D.what
现在知道D是不可能的,不清楚要不要加that,求分析,
答
C 后面只有一个从句,一个从句只能有一个引导词