Unit 4 Section ⅡUsing languages-【金版新学案】2023-2024学年新教材高二英语选择性必修第二册同步课堂高效讲义教师用书（外研版2019）

Section Ⅱ　Using languages it作形式主语 观察下面教材中的句子，写出形式主语it所提到的内容并体会其语法特征 1．But it is vital not to take any chances. not to take any chances 2．When I saw the tragic scenes on the news，I felt it was my duty as a doctor to go there and offer my help. to go there and offer my help 3．It is important to remember that Ebola doesn’t respect national boundaries. to remember that Ebola doesn’t respect national boundaries 4．It is so inspiring to have colleagues like Wilton，Maisy and Alfonso，not to mention all the others I have worked with. to have colleagues like Wilton，Maisy，Alfonso 5．In a world still facing so many problems，it is absolutely essential for us all to collaborate to create a global community with a shared future of peace and prosperity. for us all to collaborate to create a global community with a shared future of peace and prosperity 当动词不定式(短语)、动词­ing形式(短语)或者从句作句子的主语时，通常用it作形式主语代替它们，而将真正的主语放在后面，以保持句子结构的平衡。此时it只起先行引导作用，本身无词义。 知识点1　it代替动词不定式(短语)作形式主语 it代替动词不定式(短语)作形式主语的常见句型： 1．It＋be＋形容词＋(for/of sb.) to do sth. [名师点津]　如果此句型中的形容词描述动词不定式所表示动作的特征，介词用for；如果形容词描述的是人的品质、性格，介词用of。 It is very important for us to learn how to deal with stress. 学会如何应对压力对我们来说很重要。 It was really very kind of you to give me a lift home. 你让我搭便车回家，真是太好了。 2．It＋be＋名词(＋for sb./sth.)＋to do sth. It is a shame for us to have lost the game. 我们输了这场比赛，真丢人。 It is good manners for students to greet to their teachers. 学生向老师打招呼是礼貌的行为。 3．It takes sb.some time to do sth.做某事花了某人……时间 It took them a year to build the bridge. 建这座桥花了他们一年的时间。 4．It’s up to sb.to do sth.做某事是某人的职责或义务 It’s up to us to help those in need. 帮助那些有困难的人是我们的重任。 ◎即学即练——单句语法填空 (1)It is essential for you to accomplish the papers before Sunday. 学生用书↓第82页 (2)It’s clever of you to work out the maths problem. (3)It is necessary for high school students to learn (learn) another foreign language. 知识点2　it代替动词­ing形式(短语)作形式主语 it代替动词­ing形式(短语)作形式主语的常见句型： It’s no use/no good/useless/a waste of time/...＋doing sth. It is useless giving him some advice. 给他提一些建议是