的黑体部分不能单独作谓语。

　　一、主语

　　1．主语的概念及构成

　　主语是一个句子叙述的主体，是句子所要说明的人或事物，表示句子描述的是"谁"或"什么"。主语通常由名词、名词化的形容词、代词、数词、动词不定式(短语)、动名词(短语)或从句等担当。

词类 例句 名词 The news is exciting. 名词化的

形容词　 The disabled are well cared for in our country. 代词 None of us believed what he said. 数词 One­third of the work has been finished. 不定式 To decide is to act.(决定即行动) 动名词 Watching a film is a pleasure. 从句 Whether he will leave is unknown. 　　

　　[即时演练1]

　　(1)用所给词的适当形式填空

　　①The children (child) are playing on the swings in the park.

　　②In my opinion, swimming (swim) is more difficult than anything else.

　　③Each of us (we) is different.

　　④Three­fourths (three­fourth) of the surface of the earth is sea.

　　⑤To_teach (teach) the three children is my job this afternoon.

　　(2)完成句子

　　①What_he_said_at_the_meeting (他在会议上说的话) left a deep impression on me.

　　②Drinking_a_cup_of_wine (喝杯葡萄酒) can make me feel relaxed.

　　③It is difficult to_learn_English_well (学好英语) if you don't work hard.

　　2．主语的常考点

　　(1)不定式作主语时，常用it作形式主语。

　　It is not easy to grow fruit trees and vegetables here.

　　在这里，种果树和蔬菜不容易。

[名师点津]　①用于句型"It is＋adj.＋for sb. to do sth."中常见的形容词(用于说明