Unit 4 Topic 3 Section A（难点突破）1. We will be able to do anything that can be done on the earth .注意：that can be done on the earth .定语从句修饰anything.从句的谓语用的是带有情态动词的被动语态。2. He thinks they are reading on the Internet in order to learn about human culture.注意：in order to 为了，表示目的，后接动词不定式，相当于so as to . in order to 既可放在句首又可放在句中； so as to 只能放在句中，不能放在句首。它们的否定形式都是在 to前加not,既in order not to , so as not to .它们后只能接动词原形，如果后接目的状语从句可用in order that 或 so that . They did anything in order to so as to make money . She went to English last year in order that so that she could learn standard English.3. I dont think aliens can be found in space . 注意： 当 think, believe, suppose, imagine, expect等动词后接的宾语从句含有not等否定词时，该否定应移至主句，即否定主句的谓语动词。I dont think it will rain tomorrow. 我认为明天不会下雨。当主句的主语是第二、三人称时，否定式一般不转移。He suppose they wont win the game .他猜想他赢不了比赛。 注意：改写反意疑问句时，当主句的主语是第一人称时，反意疑问句的主、谓要与从句一致。如果主句的主语是第二、三人称时，反意疑问句的主、谓要与主句一致。He thinks he can make it ,doesnt he ? I dont think it will rain tomorrow ,will it ?4. I wont believe there are aliens until I see them with my own eyes .Not, until 直到，才，遵循主将从现的时态原则。I wont go until you come back. 你不回来，我不走。 注意：当主句的动词为wait , watch, think等延续性动词时不与not连用。We will wait for you until twelve oclock . 我们将等你到12点钟。