The finally ______(arrive)______(介词）the small village when it was dark.
问题描述：
The finally ______(arrive)______(介词）the small village when it was dark.
答
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）