They arrived at a farmhouse,in front of

网友回答

填 which ,in front of which相当于where~
======以下答案可供参考======
供参考答案1:
填 which
这个是 which 引导的非限定性定语从句，which 做介词短语 in front of 的宾语
供参考答案2:
They arrived at a farmhouse, in front of (which) sat a small boy.