英语从句填空The first of September is the day( ) the school year starts.（ ）they have not left yet is clear so far.

英语从句填空The first of September is the day( ) the school year starts.（ ）they have not left yet is clear so far.
英语从句填空
The first of September is the day( ) the school year starts.
（ ）they have not left yet is clear so far.

英语从句填空The first of September is the day( ) the school year starts.（ ）they have not left yet is clear so far.
when
What

when：when引导定语从句，相当于on which，意思是on the day
9月1日是学校开学的日子。
Whether
他们是是否离开还不清楚。

第一空：on which 第二空：What 这两句应该不是连贯的吧、、、、