the house built of _______was once used as a warehouse
问题描述:
the house built of _______was once used as a warehouse
答案stone
为嘛不用stones
答
石头的意思时,可数的
She stepped on a loose stone and twisted her ankle.
她踩到一块松动的石头上,扭伤了脚踝.
石材的意思时,是不可数的
The house is made of stone,not concrete.
那房子是石造的,不是混凝土造的