I will meet my best friend ______ the morning of May 1st.

题目

I will meet my best friend ______ the morning of May 1st.
A. in B. on C. at

答案

答案B 用on ,本来“早上”（morning）,下午“afternoon",晚上”evening“,前面的介词用in ,但表示具体哪一天的”早上,下午,晚上“就要on 了