Question

People used to build houses of stone and wood, but now many other m ________ are used to build houses as well.

Answer

materials

【解析】

句意：人们过去用石头和木头建造房屋，但现在许多别的材料也被用来建造房屋。

空处的词在many other之后，应为可数名词的复数形式；结合前句句意和首字母提示可知，空处的名词应是“材料material”的复数形式materials，故答案为materials。