(
课件网) B5U4 Using language Observe the rules Look at the sentences and answer the questions. Sentences (a) and (c) are from the reading passage. Activity 1 a But it is vital not to take any chances. b But not to take any chances is vital. c It is important to remember that Ebola doesn’t respect national boundaries. d To remember that Ebola doesn’t respect national boundaries is important. 1 What does “it” refer to in sentences (a) and (c) 2 What is the difference between the sentences in each group Why does the author choose to use sentences (a) and (c) instead of (b) and (d) Observe the rules Look at the sentences and answer the questions. Sentences (a) and (c) are from the reading passage. Activity 1 a But it is vital not to take any chances. b But not to take any chances is vital. c It is important to remember that Ebola doesn’t respect national boundaries. d To remember that Ebola doesn’t respect national boundaries is important. The first sentences in each group use “it” as an empty subject at the beginning of the sentences. The reason why sentences (a) and (c) are chosen is that the sentences are kept balanced and the key information of the sentences is emphasised. Observe the rules Now look for more sentences with this structure in the reading passage, and summarise its use in your own words. I felt it was my duty as a doctor to go there and offer my help. It is so inspiring to have colleagues like Wilton, Maisy and Alfonso, ... ..., it is absolutely essential for us all to collaborate to create a global community with a shared future of peace and prosperity. Activity 1 it 作为形式主语，所代替的是句子的逻辑主语，并无实际词义。这可以保持句子的结构平衡，避免主语太长，显得头重脚轻。 it 作形式主语 It as an empty subject 1. 代表不定式 (1) It + be + 形容词 + 不定式 e.g., It is difficult to translate the book. (2) It + be + 名词 + 不定式 e.g., It was her duty to clean the room. (3) It + be + 介词短语 + 不定式 e.g., It was against my principle to do that. (4) It + 及物动词 + 宾语 + 不定式 e.g., It cost 150 yuan to buy the dress. It as an empty subject 2. 代表动名词 it 代表动名词时，一般以“be + 名词”作谓语，也可以以“be + 形容词”作谓语。 e.g., It is no use doing that. It is pleasant sitting here. no use/no good/useless/ senseless/fun/tiring/nice/ good/interesting/a waste of/ a wonder + v-ing It is + It as an empty subject 3. 代表从句 (1) It + be + 形容词 + 从句 e.g., It is natural that she knows everything about it. (2) It + be + 名词 + 从句 e.g., It is a question how he did it. (3) It + 动词的被动语态 + 从句 e.g., It is not decided who will take over the company (4) It + be/其他系动词 + that 从句 e.g., It may be/seems that he views the issue from a different perspective. It as an empty subject 常用句型 (1) It is clear/obvious/true/possible/certain/... that... 很明显他迟到了。 (2) It is important/necessary/right/strange/natural/... that... (should) do... 你在比赛前做足够的运动是有 ... ...
