英语从句连词as soon as , because, before, if, so, so that, until...答:2.原因状语从句(1)常由because, since, as引导。(2)because表示直接的原因,着重点在从句,用于回答why,语气最强。I can’t go to school because I am ill.since一般表示对方已知的,无须加以说明的既成事实的理由,全句中心在主句,语气比because弱,常译为“既然”,如:Since you are ill, ...