对since 画线提问用什么词作疑问词?
问题描述：
对since 画线提问用什么词作疑问词?
答
用问时间长短的词提问,如:how long,how many years/months等.
答
用how long
答
用how long.
例如：
题目是：I have been in the army since 1999.
提问应该是：How long have you been in the army?
答
如果划了since，要用how long
如果没划，要用since when