He needs to spend time on his homework.
问题描述:
He needs to spend time on his homework.
其中的on可以改为in吗?
因为我知道有spend time (in) doing sth.既然in后面可以跟动名词,那好像就可以跟名词的吧?
答
He needs to spend time on his homework.==He needs to spend time( in) doing his homework