He was born on a very cold night _A_ December A of B in c on答案为什么选A而不选B或C?

He was born on a very cold night _A_ December A of B in c on答案为什么选A而不选B或C?
He was born on a very cold night _A_ December A of B in c on
答案为什么选A而不选B或C?

He was born on a very cold night _A_ December A of B in c on答案为什么选A而不选B或C?
一般是说at night的,介词at与其相搭配,但是具体说到是哪一个夜晚的话,就得用介词on.比如说"on the night you were born" .
拓展开来,morning一般是与介词in搭配,有“in the morning”的说法,但是具体说到是怎么样的一个早晨的时候,也要用介词on.比如说“on the morning of September"
至于为何不选in 或者on的话,就要看英文句子的结构.表达时间的时候,具体到时刻时有“at 8:00 in the morning"的说法,对于其他情况则没有“at the night of Dec."这样的表达.
PS:好久木有接触过中学英语了,感觉自己表达得有些结巴……希望能看得懂~