The teachers in our school had some activities_______the afternoon of March 28.A.in B.on

题目

The teachers in our school had some activities_______the afternoon of March 28.A.in B.on

答案

很高兴能够在这里回答你的问题,
选B
具体到某一天时,前面要用介词on
这里是三月28号那天的下午,已经具体到那天了,所以要用on
3月28日下午,我们学校的老师举行了一些活动.