When Mr.Wang return ___ China from America,he worked in Beijing as a teacher.(填介词）
问题描述：
When Mr.Wang return ___ China from America,he worked in Beijing as a teacher.(填介词）
答
to
return 介词总是 from/to
Mr.Wang -- 单数,叙述的事情是过去,后面的动词 “return” 要有变化.题目里怎么不变?