The city council arranged for the old houses to be pulled down as quickly as possible.

pulled 是动词 pull 的过去分词形式，pull 的基本意思是"拉、拖"。 down 是副词，表示"向下"的方向。 pulled down 是一个短语动词，字面意思是"向下拉"，引申为"拆除建筑物"的意思。