Do you still remember the day ___you first came to shanghai?A.that B.in which C.on which D.which 为什么介词用on
问题描述：
Do you still remember the day ___you first came to shanghai?
A.that B.in which C.on which D.which 为什么介词用on
答
on this(that) day 是个固定用法
答
因为原句是：
You first came to Shanghai on the day.
所以这里将on前移和which搭配，on which=when
再如：
Do you still remember the city in which you first lived? (You first lived in the city，所以此处则用in which，相当于where)
答
on the day
星期,日,月,都要用on 比如：on that day,on Friday,on March
年用in 比如：in 1999.
但是如果年月日一起就用on,比如：on the 1st,1999.(只要有日,就用on)