8. - Hello. May I speak to Bill, please?

- ____.　　 A. Bill speaking　　　　　　　　　　　 B. I’m Bill

C. You are speaking to Bill　　　　　　 D. I’m speaking

7. - ____.

- Thank you. I certainly will.　　

A. Happy birthday to you　　　　　　　　　 B. Let me help you with your English

C. Please remember me to your grandparents　D. Don’t forget to post the letter

6. - Would you do me a favor and carry these books?

　- ____.　　 A. Yes, that’s right　　　　　　　　 　 B. No trouble

C. Never mind　　　　　　　　　　　　　 D. With pleasure

5. - Thank you ever so much for the present you brought me.

　 - ____.　

　A. No,thanks　　　　　　　　　　　　 B. I’m glad you like it

　C. Please don’t say so　　　　　　　 D. No, it’s not so good

4. - Sorry, I couldn’t come to the party. I was sick that day.

- ____.　 A. I don’t know that　　　　　　　　　 B. That’s all right

C. Yes, we’ll have another party　　　 D. No, the party wasn’t held

3. - Have you got time on Monday?

　- ____　 A. Of course not.　　　　　　　　　　　 　B. It’s certain.

C. You can say that again.　　　　　　　 D. Why? I’ll stay at home.

2. ?Wasn’t it Dr Wang who spoke to you just now?

　- ____.　 A. I didn’t know he was　　　　　　　 B. Yes, it was

C. No, he wasn’t　　　　　　　　　　　 D. Yes, he did

14、(1)钢　 (2)24.4%

13、(1)镁、铁的活动性比铜强；(2)镁和稀盐酸反应比铁与稀盐酸反应剧烈

　 2Mg+O₂2MgO　 (3)铁在自然界中以化合物的形式存在，而金在自然界中以单质形式存在

12、铁与空气中的氧气、水发生复杂的化学反应而形成铁锈；铁锈疏松多孔，能让水分和空气中的氧气穿过它的空隙，不断向里层渗透，继续和铁反应，直至铁被完全锈蚀。