Amy arrived ___ home ___ a rainy night.(介词）

at home
on night

Amy arrived (at) home (on) a rainy night.(介词）

at home
on night

/; at
(at night, in the evening) (arrive home,或者 arrive at home都行 )

arrive 是不及物动词,所以加介词at在后面
具体说明是哪个晚上,用介词on

at on