The plane land for thirty minutes.for thirty minutes划线提问用how soon还是how long?

题目

The plane land for thirty minutes.for thirty minutes划线提问用how soon还是how long?
急

答案

how long does the plane land for?
how long 问时间长度.
how soon是多快,
例如：how soon can you finish the work.
一般这样回答 In half an hour.注意这个in .