5、“since+过去时的从句”、“since+一段时间+ago”。且for与since引导的时间状语可以相互转换。e.g.Myunclehasworkedatthisfactoryfortenyears.=Myunclehasworkedatthisfactorysincetenyearago.I’ve lived here since 1990.自从1990年以来我就住在这里。 I haven’t seen him for three years.我三年没有看见他了。 She’s been at this school since five
6、 years ago. 自从五年前以来她就在这个学校。Step34aRewritethesentencesusingfororsince.JimisinJapan.Hearrivedtherethreeyearsago.JimhasbeeninJapanforthreeyears.2.Theyareveryhungry.Theirlastmealwastenhoursago.Theyhavebeenhungryfortenhours/sincetenhoursago.3.Ihaveacamera.Iboughtitin2009.Ihaveh