Unit 4 Global warming Section Ⅲ Grammar——it 的用法(Ⅱ)一、it 引导强调句型1．强调句型的基本结构：It is/was＋被强调部分＋that/who＋其他成分(1)此结构中 it 没有具体意义，只是引出被强调部分。(2)此强调句型只能强调主语、宾语、状语，不能强调谓语。(3)强调时间状语、地点状语、原因状语等时要用 that 而不能用 when, where, because。(4)被强调的成分是表示人的词时用 who/that，而被强调部分是物时只能用 that。如：It is my mother that/who reminds me to get up on time every day.每天都是我妈妈提醒我按时起床。It was Mr Smith who/that/whom he turned to for help.他是向史密斯先生求助的。It was in the museum that I first saw this old ancient vase.我是在博物馆里第一次见到这个古花瓶的。It is every Sunday that they get together to have a good time.每个星期天他们聚在一起来度过愉快的时光。It was by train that they travelled to Tibet last summer.去年夏天他们乘火车去了西藏。2．强调句型的时态：(1)如果原句中谓语动词的时态是现在或将来时间范畴的时态(如一般现在时、现在进行时、现在完成时、现在完成进行时、一般将来时、将来进行时、将来完成时等)，强调句型的时态为 It is＋被强调部分＋that/who＋其他成分。(2)如果原句中谓语动词为过去时间范畴的时态(如一般过去时、过去进行时、过去完成时、过去将来时等)，强调句型的时态为 It was＋被强调部分＋that/who＋其他成分。如：A meeting will be held next week in the meeting room.→It is next week that a meeting will be held in the meeting room.We go to work every day by bus.→It is by bus that we go to work every day.The couple have got separated from each other recently.→It is recently that the couple have got separated from each other.They bought an expensive apartment the other day.→It was the other day that they bought an expensive apartment.When they arrived at the airport, the plane had already left.→It was when they arrived at the airport that the plane had already left.3．强调句型的疑问形式：(...
