题目内容

【题目】充分燃烧某糖,消耗的氧气、生成的CO2和H2O的物质的量都相等,它的相对分子质量是它实验式的5倍,0.1 mol该糖能与24 g乙酸发生酯化反应,且该糖能与银氨溶液发生银镜反应。求:

(1)该糖的实验式。

(2)该糖的相对分子质量、分子式。

(3)若该糖是直链分子,同一个碳原子上连有2个羟基不稳定,推导出它的结构简式。

【答案】(1)CH2O

(2)150 C5H10O5

(3)CH2OHCHOHCHOHCHOHCHO

【解析】据充分燃烧某糖,消耗的氧气、生成的CO2和H2O的物质的量都相等可得出实验式为CH2O,再据它的相对分子质量是它实验式的5倍可确定其相对分子质量和分子式分别为150和C5H10O5;然后确定它的分子结构:0.1 mol该糖能与24 g乙酸发生酯化反应,且该糖能与银氨溶液发生银镜反应,首先说明该糖分子中同时有羟基和醛基,根据0.1 mol该糖能与24 g乙酸发生酯化反应,可计算出羟基数目为4个。

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【题目】 完形填空(共20小题;每小题1.5分,满分30分)

阅读下面短文,从短文后各题所给的A、B、C和D四个选项中,选出可以填入空白处的最佳选项。

I dont know whats your opinion about mountains.

It was only in the eighteenth century 21 people in Europe began to 22 that mountains were beautiful. 23 that time, mountains were feared by the people 24 on the plain, especially by the city people, 25 they were wild and 26 places 27 one was easily 28 or killed by terrible animals.

Slowly, however, 29 people 30 were living comfortably in the towns began to grow __31__ them. They began to feel 32 looking for wild excitement, as their attention turned from the man-made town to the 33 country; and to places 34 dangerous and wild. So high mountains began to be 35 for a holiday.

Then, mountain-climbing began to grow popular 36 . To some people, there is something 37 about getting to the 38 of a high mountain: a struggle against nature is finer than a battle 39 other human beings. And after a difficult climb, what a 40 reward it is to look down on everything within sight.

【1】A. when B. which C. that D. and

【2】A. regret B. seem C. hope D. think

【3】A. After B. Before C. During D. At

【4】A. lived B. living C. to live D. who living

【5】A. whom B. for whom C. with whom D. to whom

【6】A. danger B. dangerous C. dangerously D. dangerless

【7】A. that B. which C. where D. in where

【8】A. lost B. missed C. found D. searched

【9】A. many B. much C. many the D. a lot

【10】A. that B. who C. whom D. /

【11】A. tiring with B. tiring of C. tired with D. tired of

【12】A. interesting B. interest in C. interested D. interested in

【13】A. untouched B. touched C. untouching D. touching

【14】A. where was B. which were C. which that was D. which it was

【15】.A. excited B. expensive C. popular D. terrible

【16】A. for sport B. as a sport C. with a sport D. like a sport

【17】A. pleasure B. pleased C. pleasant D. unpleasant

【18】A. top B. middle C. bottom D. foot

【19】A. about B. for C. without D. against

【20】A. disappointed B. satisfied C. satisfactory D. disappointing

【题目】七选五型阅读理解

(2017·浙江)How to Do Man-on-the-Street Interviews

The man-on-the-street interview is an interview in which a reporter hits the streets with a cameraman to interview people on the spot. 1 But with these tips, your first man-on-the-street interview experience can be easy.

When your boss or professor sends you out to do man-on-the-street interviews for a story, think about the topic and develop a list of about ten general questions relating to it. For example, if your topic is about environmental problems in America, you might ask, "Why do you think environmental protection is important in America?" 2

Hit the streets with confidence. 3 Say, "Excuse me, I work for XYZ News, and I was wondering if you could share your opinion about this topic." This is a quick way to get people to warm up to you.

Move on to the next person if someone tells you she is not interested in talking on camera. Don’t get discouraged.

4 Each interview that you get on the street shouldn’t be longer than ten minutes. As soon as you get the answer you need, move on to the next person. Make sure that as you go from interview to interview, you are getting a variety of answers. If everyone is giving you the same answer, you won’t be able to use it. A safe number of interviews to conduct is about six to ten. 5

If your news station or school requires interviewees to sign release forms to appear /span>on the air, don’t leave work without them.

A. Limit your time.

B. As you approach people, be polite.

C. If you don’t own a camera, you can buy one.

D. For new reporters, this can seem like a challenging task.

E. To get good and useful results, ask them the same question.

F. That number of interviews should give you all the answers you need.

G. With a question like this, you will get more than a "Yes" or "No" reply.

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