LI Ming ----50 dollars buying gifts for his familya,cost b.costs c.spend d.spent说下为什么

问题描述:

LI Ming ----50 dollars buying gifts for his family
a,cost b.costs c.spend d.spent
说下为什么

d

D
spend的主语是人
cost的主语是物
所以排除AB
因为给他家买礼物是过去的事情了
所以用过去式spent
所以选D
sb spend sth doing sth 是一个句型