Unit 3Teenagers should be allowed tochoose their own clothes.SectionA1. I don’t think sixteen-year-olds should be allowed to drive.我认为不应该允许 16 岁的人驾驶汽车。【要点指津】(1) 在主从复合句中,当主句的主语是第一人称,谓语动词是 think, believe, suppose 等时,要将从句的否定词转移到主句中,即主句的谓语动词用否定式,而从句的谓语动词用肯定式。(2)sixteen-year-olds 是由复合形容词 sixteen-year-old 衍化而来的,意为“十六岁的青少年”。“数词+名词+形容词”可以构成复合形容词,其中的名词要用单数形式,且用连字符连接。【同步互动】①I think students should be allowed to do homework withfriends.( 改为否定句 )I _______ think students ________ be allowed to do homeworkwith friends.② 这棵苹果树有 6 米高,而那是一棵 10 米高的橡树。The apple tree is ________ ________ ________, but that treeis a _____________ oak.don’tshouldsixmeters tallten-meter-tall③Bill said they were going to have ________ holiday.BA. a two-weeks’B. a two-weekC. two weeks’D. two weeks解析:名词 holiday 前应用形容词,可排除 C 、 D 项;复合形容词中的名词应用单数,且不需要用所有格。故选 B 。2. They aren’t serious enough. 他们不够严肃。【要点指津】enough 意为“足够地 / 足够的”,作副词对形容词和副词进行修饰时,要跟在其后;作形容词对名词进行修饰时,要置于名词之前。【同步互动】—What do you think of the lecture of Li Yang’s Crazy English?—I think it’s ________, but someone thinks it’s much too________.A. wonderful enough; boredB. enough wonderful; boringCC. wonderful enough; boringD. enough wonderful; bored解析: enough 在此处用作副词来修饰形容 wonderful ,故要放在被修饰词的后面;主语 it 指代“李阳疯狂英语讲座”,所以要用形容词 boring 表示“无聊的”。3. They talk instead of doing homework. 他们不做作业,却去聊天。【要点指津】instead of 是介词短语,意为“代替;而不是”。辨析instead of 与 instead①instead of 是介词短语,其后可接名词、代词、动名词或介词短...