___ Christmas,people are often busy ____ shopping.

问题描述:

___ Christmas,people are often busy ____ shopping.
A.At...going B.At...go C.On...going D.On ...go
为什么不是A,
At Christmas不就是解释在圣诞节吗?是不是答案错了?On Christmas Eve

答案的确是C
我帮你分析一下:
首先:在某个节日前是要用介词on的,如on mother's day (在母亲节)这里就不能说at mother's day
其次有一个短语(be busy doing sth)这你应该知道,不然你不会选A