there is a halloween party_______8p.m________october 31 every year.

问题描述:

there is a halloween party_______8p.m________october 31 every year.
at on
on of

there is a halloween party____at___8p.m____on____october 31 every year.
具体时刻用介词at,具体哪天用on,如:at 6:00am on Monday