"条件"表达法是中学英语中相当重要的语法现象,对"条件"表达法的了解,同学们不能只停留在"if"引导的"条件"句上。实际上,"条件"表达法的意义相当广泛,为了使同学们更好地复习和了解"条件"表达法的考点和用法,本文拟就"条件"表达法的考点及相关知识归纳如下。
一、考查"when, if, unless"引导的条件句的用法
典型题例
①Don't be afraid of asking for help ______ it is needed.
A. unless B. since C. although D. when
②The WTO can't live up to its name ______ it does not include a country that is home to one fifth of mankind.
A. as long as B. while C. if D. even though
③You'll succeed in the end ______ you give up halfway.
A. even if B. as though C. as long as D. unless
解析:when, if, unless充当从属连词,其意义分别为"如果","除非、如果不"。如:When there is no gravity, our feet no longer stay on the ground.如果没有地球引力,我们就不可能站在地面上。You will be late unless you leave immediately.快点走吧,要不然你会晚的。
特别提示:在if, when, unless等引导的条件句中,应当注意时态的对应性。一般来讲,if引导的条件句常用一般现在时表将来,而主句常用一般将来时。如:If it doesn't rain tomorrow, we will hold the sports meet.如果明天不下雨， |
