10.We shall never forget the days ___ we worked together.
A.that B.in which C.on which D.which
z这道题选B,为什么不选C?
在那些天 不是on those days么
7.I will never forget the day____ we studied together.
A.at which B.on that
C.at that D.on which
这题为什么又选D?