The finally ______(arrive)______(介词）the small village when it was dark.

The finally ______(arrive)______(介词）the small village when it was dark.
The finally ______(arrive)______(介词）the small village when it was dark.

The finally ______(arrive)______(介词）the small village when it was dark.
They finally arrived at the small village when it was dark.
由后面的was可知 这个句子是过去时 所以arrive要用过去形式
至于at 哈哈 大家都知道 arrive at（后接具体地点） 固定用法
（arrive in 后接大地点 如城市 国家等）