解析：此句的主语是mathematics，即学科作主语，是表示单数的意义的词，故只能在选项A和B二者中选择，而选项A时态不对，故正确答案为B。句子的意思是：“数学和其他学科一样，是自然科学。”
16 Either of these young ladies____________perfectly qualified to teach Greek, Latin and French.
A. wereB. areC. isD. have been 正确答案：C
解析：当 either, each, neither, everyone等不定代词作主语时，其后谓语需用第三人称单数，例如“Neither of these books is very new.这两本书都不新。”、“Each of the students brings a dictionary.学生各自带字典来。”和“Every man and woman is eligible to vote.每个男人或女人都有资格投票。”，故正确答案为C。句子的意思是：“这些年轻女士中的任何一位，都能出色地胜任教希腊语、拉丁语和法语。”
17 Large quantities of water ____________cooling purposes. A. are needed forB. is needed toC. are need toD. is need for 正确答案：B
解析：表示数量的名词应作单数看待，故正确答案是B。句子的意思是：“需要大量的冷却用水。”
18 Copper as well as most metals ____________.
A. is a good conductorB. is a good insulatorC. are good conductorsD. are good insulators 正确答案：A
解析：as well as 在此并不是表示与主语并列关系，该句的主语仅仅是copper，故正确答案为A（conductor意为“导体”，insulator意为“绝缘体”）。句子的意思是：“和大多数金属一样，铜是一种很好的导体。”
19 There used to be some trees by the lake, ____________? A. was thereB. were thereC. weren't thereD. wasn't there 正确答案：C
解析：there used to be句型相当于there be句型，所以反意疑问句部分应该用be提问，而且动词的数应与后面的名词一致，故正确答案为C。句子的意思是：“过去在湖的旁边有一些树，不是吗？”
20 War and peace ____________a constant theme in the history of the world. A. isB. areC. have beenD. has been 正确答案：A
解析：当and连接的两个名词是指同一个人或同一件事时，若and后的名词前没有冠词，谓语动词应该用单数形式；若and后面的名词前有冠词，谓语就用复数形式。此句中没有冠词，因此用单数，故正确答案为A。句子的意思是：“战争与和平是世界历史上一个永恒的主题。”
11-20 考核知识点：主谓一致，参见P239
三、交际用语(从每个对话中未完成的部分四个选项中，选出最佳选项) 10%
1 — Seven thirty? I guess I'd better get going for the meeting at eight o'clock. When is the next bus up to the hotel? —____________
A. That bus leaves here in 15 minutes. B. That bus left just now. C. That bus isn't here.
D. The bus over there is waiting. 正确答案：A
解析：第一说话人要赶去酒店开会，问下一趟车什么时候开，第二说话人告诉他十五分钟以后有下一趟车，所以正确答案为A。
2 — What's happening with the new teaching building? —____________ A. It's not an easy job. B. I've just come back.
C. I've never been there before.
D. It's held up by the bad weather this week. 正确答案：D 解析：第一说话人询问新教学楼的进展情况，第二说话人告诉他施工因受到本周天气的影响而暂停，所以正确答案为D。
3 — Do you know John's new address? Here's his mail and I want to send it to him. —____________
A. Sorry, I don't think I will do this. B. Well, we used to be roommates. C. Well, we will never meet again.
D. Sorry, we didn't get along before he moved. 正确答案：D
解析：第一说话人想把邮件寄给约翰，因而询问他的新地址，第二说话人说约翰搬走前两人相处不好，言下之意不知道约翰的新地址，所以正确答案为D。
4 — I?d like to talk to Professor Li, please. — ____________
A. Oh, you have bad luck.
B. He's stepped out of the office for a little while. C. I'm sorry that it's too late. D. Who are you, please? 正确答案：B
解析：第一说话人要找李教授谈话，第二说话人告诉他李教授刚出办公室不久，所以正确答案为B。其他选项均不符合礼节和英语习惯。
5 — Why are you interested in working for our company? —____________
A. Because I need to support my family.
B. Because your company has a good reputation. C. Because I just graduated from university. D. Because you can give me a high salary. 正确答案：B
解析：第一说话人（公司领导）问求职者为何对该公司感兴趣，第二说话人（求职者）解释说是因为公司声誉很好，所以正确答案为B。选项A、C和D都不是明智的回答。 本大题考核知识点：交际用语，参见P242 四．英译汉：20%
Like other \addiction is for work, career, or a belief that they are \
right\worth.Often, this is a sign of insecurity or having priorities out of order.
Workaholics will spend most of their lives at work or taking work home with them.They will often have little time for personal lives — family, hobbies, or relaxation.Having a balance is not just a preferable desire; it is needed for overall mental, physical, spiritual, and emotional health.
本大题考核知识点：课文的理解与翻译，参见P214