2. The birds in the cage which I bought yesterday 不是

1. Birds can fly 是

3. 不要把从句的谓语当成句子的谓语, 或把主句的谓语当成从句的谓语。

　如果是一个复合句，主句和从句都应该分别有自己的主语和谓语。

　典型错误：

1) 1)　 Those who eat too much will easily ill.

∟Those who eat too much will easily get ill.

　2) When he walking in the park, he felt a little tired.

　 ∟When he was walking in the park, he felt a little tired.

　3)When I at school, I studied very hard.

　 ∟When I was at school, I studied very hard.

II. Practice: 判断以下是否是句子。

2. 一个句子不能同时有两个谓语。

　典型错误：

1) The old man likes take a walk in the village after supper.

　 ∟The old man likes to take a walk in the village after supper.

　2) I enjoy talk with him over a cup of coffee.

　∟I enjoy talking with him over a cup of coffee.

　3) The boy ran to his mother cry.

　∟The boy ran to his mother crying.

　4) After write the notice, he put it up on the wall.

　∟ After writing the notice, he put it up on the wall.

　 After he wrote the notice, he put it up on the wall.

对英语句子的认识

意义：英语的句式与中文的不同。我们在学习英语的时候要注意到这一点。有的同学在学习中对此没有足够的认识，常常受中文的干扰。在写作中表现出不能写出正确的句子。

I. 什么是句子？

　长的是句子，短的是词。×

　√ 无论字数多少，只要有主语和谓语(动词)，而且能表达完整的意义的一句话就是一个句子。

I am tired.

Pressing one’s palm together and resting one’s head on the back of one’s hand while closing the eyes as if sleeping means “I am tired.”(双手合拢，闭上眼，把头靠在手背上像睡觉的样子，意思是说“我累了。”)

　这两个句子都具备了主语和谓语。都是完整的句子。要记住：在英语中，一个句子必须且只能有一个谓语。

1. 省略主语的句子

Come in, please. (You)

Open the door.

Sit down.

Stand up.

What a day! (What a terrible day it is!)

22、OH^-　 Cl^-　 K⁺；　 铁粉；　 Ag(或银)；

Ag⁺　 Fe³⁺　 Cl^-　 OH^-；　 KNO₃

21、(1)Fe²⁺、Fe³⁺、Cu²⁺、MnO₄^- (2)NH₄⁺、Mg²⁺、Al³⁺ (3)S^2-、CO₃^2-、HCO₃^-(4)Ba²⁺、 SO₄^2-

(5)Cl^-、NO₃^-、Na⁺

20、①　 H₂O₂ + 2I^- + 2H⁺ = I₂ + 2H₂O　 ② +2价

19、(1)含有Ba²⁺、Ca²⁺离子中的一种或两种，因为BaSO₄不溶于水，CaSO₄微溶于水。　　　 (2)Fe(OH)₃　 　　　　

(3)2AlO₂^-+CO₂+3H₂O=2Al(OH)₃↓+CO₃^2-

或AlO₂^-+CO₂+2H₂O=Al(OH)₃↓+HCO₃^-

13、A　 14、B　 15、C　 16、C　 17、A　 18、A