题目内容：

-_____ will your father get back from America?
-I am not sure.He says he won't be back until next December.
A.How long B.How soon C.How often D.When

优质解答

when 是用来问什么时候的,所以选择D 根据后面的回答,是问你爸爸什么时候从美国回来
how long 多长
how soon 多快
hwo often 问频率