2)条件状语从句 条件状语从句主要由以下连词引导：if,unless,providing/provided(that),suppose/supposing(that),oncondition(that),as/solongas,incase等。 Solongasyouworkhard,youwillsurelyachievegoodresultsinexaminations. IshallreturnnextThursdayunlesssomethingunexpectedhappens. Iwillgoprovidedthatyougowithme. PleasegivethislettertoJohnincasehecomes.
