第三课时SectionA(GrammarFocus～3c)单元同步语法精讲含有if引导的条件状语从句的主从复合句由一个主句和一个或一个以上的从句构成的句子叫复合句。若由连接词引导的句子在复合句中表示条件，作主句的条件状语，则该句子被称为条件状语从句。1．条件状语从句的引导词。条件状语从句通常由连词if(如果，假如)，unless(＝if…not，除非，如果不)引导。eg：Youwillgetgoodgrades，ifyoustudyhard.如果你努力学习，就会取得好成绩。Ifyoudon'tleaverightaway，youwillbelate.如果你不马上来，你将会迟到的。2．条件状语从句的位置。条件状语从句既可以放在主句之前，也可以放在主句之后。如果放在主句之前，要用逗号与主句隔开；如果放在主句之后，中间不必用逗号。eg：Ifitdoesn'traintomorrow，wewillgoshopping.如果明天不下雨，我们将去购物。Youcanpasstheexamifyoustudyhard.如果你努力学习，你就会通过考试。3．条件状语从句的时态。若主句为将来时态或是含有情态动词的句子或祈使句，则条件状语从句用一般现在时。eg：Hewillnotleaveifitisn'tfinetomorrow.如果明天天气不好，他就不会走。(主句用一般将来时，从句用一般现在时)Ifhecomes，letmeknow.如果他来，让我知道。(主句是祈使句，从句用一般现在时)单元同步语法强化训练一、用括号中所给单词的适当形式填空。1．You________(look)youngerifyou________(wear)thisnewdress.2．Ifwe________(get)uplate，we________(have)notimeforbreakfast.3．Ifthere________(be)afire，I________(call)119forhelp.4．Susan________(come)ifyou________(have)abirthdayparty.5．IfI________(be)freetomorrow，I________(visit)myaunt.willlookweargetwillhaveiswillcallwillcomehaveamwillvisit二、单项选择。6．Ifshe________acar，shewilldrivetoworkeveryday.A．buysB．boughtC．willbuyD．isbuying7．We________swimmingtogetherifhecomesthisafternoon.A．goB．wentC．goingD．willgo8．—What________iftheteacherknowsthefactstomorrow?—Idon'tknow.A．happensB．happenedC．willhappenD．happeningCAD9．Ifyoutakepartinthegame，you________agoodtime.A．haveB．willhaveC．havingD．had10．IwillgivehimthebookifI________himnextweek.A．meetB．metC．meetingD．willmeet11．AuntLucywilltellussomethingabouthertriptoAustraliawhenshe________back.(2014，重庆)A．comesB．cameC．wouldc...
