May 21st前用介词on还是in?
问题描述：
May 21st前用介词on还是in?
答
用on,因为它是指具体到某一天,如果时间不确定就要用in了.如,in1998,in January,on May 21st.
May 21st前用介词on还是in?
用on,因为它是指具体到某一天,如果时间不确定就要用in了.如,in1998,in January,on May 21st.