分类：教育/科学-外语学习-英语考试
问题：IhaveanEnglishquestionItisfiveda 
It is five days---we came here.A when   B before     as     D since
回答：正确答案是 nce。since的意思是“自从(一个具体的过去时间)到现在”,主句中一般用现在完成时。Itisfivedayssincewecamehere.相当于:Ithasbeenfivedayssincewecamehere.意思是:我们在这里已经有五天了。再如:WehavebeengoodfriendsSINCE1999.TheyhavelivedhappilySINCEtheygotmarriedthreeyearsago.MyEnglishhasimprovedalotSINCEIcametothisuniversity.