sometimes tom"s room __corn at harvest time(is used as)为什么不填is used for?

问题描述:

sometimes tom"s room __corn at harvest time(is used as)为什么不填is used for?

used as+名词 :一般同等意义的替换,即等价
用来当做(谷仓)来使用
is used for +目的(一般为动名词)
例:sometimes tom"s room is used for storage at harvest time