题目内容

【题目】根据你的生活经验和下表所提供的信息，分析并回答下列问题。

物理性质

物质性质比较

导电性(以银的导电性为100作标准)

银

铜

金

铝

锌

铁

铅

100

99

74

61

27

17

7.9

密度/(g·cm3)

金

铅

银

铜

铁

锌

铝

19.3

11.3

10.5

8.92

7.86

7.14

2.70

熔点/℃

钨

铁

铜

金

银

铝

锡

3410

1535

1083

1064

962

660

232

硬度(以金刚石的硬度为10作标准)

铬

铁

银

铜

金

铝

铅

9

4~5

2.5~4

2.5~3

2.5~3

2~2.9

1.5

(1)为什么菜刀、锤子等通常用铁制而不能用铅制？___________________。

(2)银的导电性比铜好，为什么导线一般用铜制而不用银制？_____________。

(3)为什么灯泡里的灯丝用钨制而不用锡制？_________________。

【答案】(1)因为铁的硬度比铅大，且铅有毒，故常用铁而不用铅制菜刀、锤子(2分)

(2)银和铜的导电性相近，但银比铜的价格贵得多，且电线用量大，所以用铜不用银(2分)

(3)因为钨的熔点(3 410 ℃)高，而锡的熔点(232 ℃)太低，通电时锡很快就熔化了，所以用钨丝而不用锡丝作灯泡的灯丝(2分)

【解析】在确定金属的用途时，要考虑其硬度、熔点、导电性等多种性质；有时还要考虑价格、资源、是否便利、是否有毒、是否利于回收等因素。正确解答本题还要会读题，要充分利用题中所给信息。

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相关题目

【题目】阅读下面短文并回答问题，注意词数要求。

[1] Ashley Power’s mother bought a computer for her when she was eight. When she was thirteen, she was surfing the Internet regularly, but she couldn’t find anywhere for teenagers to meet and talk. And one day she thought, “If I had my own website, I’d make it a really interesting site for teenagers.”

[2]So, when Ashley was sixteen, she launched her own website, called Goosehead. She had no idea how big a success it would be, but three years later, the site was the most successful teen site in the USA! It was getting 100,000 hits every day, and Ashley had about 30 employees.

[3] After a few years, the website closed down. Then Ashley, who lives in Los Angeles, was asked to write a book called The Goosehead Guide to Life. The book is about how to design a website and start a business. It begins with a section called “All About Ashley,” where Ashley tells readers what it is like to be the boss of a company when you are only sixteen. “ I was so happy. But it was crazy in a lot of ways. I got very stressed. I mean, I was only sixteen — I didn’t even have a car! If you were sixteen and you had your own company, you’d be stressed, too！“

[4] In an interview Ashley gave advice to teenagers who wanted to start their own business, “Just be strong and have your dreams and work hard at them. And don’t listen when _______, because I heard ‘no’ a lot. Just keep going until you hear ‘yes’!”

【1】 For what purpose did Ashley create GooseHead?(no more than 10 words)

__________________________________________________________________

【2】 What is the main idea of Paragraph 2？ （no more than 6 words）

__________________________________________________________________

【3】 According to paragraph 3, what did Ashley do after GooseHead closed down?(no more than 10 words)

__________________________________________________________________

【4】 How did Ashley feel as a young boss of a company?(no more than 5 words)

__________________________________________________________________

【5】 Fill in the blank in Paragraph 4 with proper words.

__________________________________________________________________

【题目】将室温（25 ℃）饲养的某种体温为37 ℃的哺乳动物（动物甲）随机分为两组，一组放入41 ℃环境中1 h（实验组）另一组仍置于室温环境中（对照组）。期间连续观察并记录这两组动物的相关行为，如果：实验初期，实验组动物的静卧行为明显减少，焦虑不安行为明显增加，回答下列问题：

（1）实验中，实验组动物皮肤的毛细血管会___________，汗液分泌会___________，从而起到调节体温的作用。

（2）实验组动物出现焦虑不安行为时，其肾上腺髓质分泌的激素会__________。

（3）本实验中设置对照组的目的是__________。

（4）若将室温饲养的动物甲置于0 ℃的环境中，该动物会冷得发抖，耗氧量会_________，分解代谢会_________。

【题目】一些腐败现象，比如“笑贫不笑贪”的羡腐心理、“朝里有人好做官”的裙带思想、“马无夜草不肥”的发财念头、“天下乌鸦一般黑”的从众迷思等等，都能从文化上找到病根。拔出这种文化病根，需要我们

①追求更加丰富多彩的文化生活

②把握正确航向和增强是非观念

③通过文化教育加以改造或剔除

④提高辨别不同性质文化的眼力

A.①④ B.②③ C.①③ D.②④

【题目】C

If you want to become a fluent English speaker you should take some advice. There are four skills in learning English. They are reading, listening, speaking, and writing. The most important thing you must remember is that if you want to improve your speaking and writing skills you should first master the skills of reading and listening.

Read as much as you can. But your reading must be active. It means that you must think about the meaning of the sentences, the meaning of the unfamiliar words, etc. There is no need for you to pay much attention to grammar or try to understand all the unfamiliar words you come across, but the fact that you see them for the first time and recognize them whenever you see them, for example in other passages or books, is enough. It would be better to prepare yourself a notebook so you can write down the important words or sentences in it.

As for listening, there are two choices: besides reading, you can listen every day for about 30 minutes. You can only pay attention to your reading and become skillful at your reading, then you can catch up on your listening. Since you have lots of inputs in your mind, you can easily guess what the speaker is going to say. This never means that you should not practice listening.

For listening, you can listen to cartoons or some movies that are specially made for children. Their languages are easy. Or if you are good at listening you can listen to VOA or BBC programs every day. Again the thing to remember is being active in listening and preferably taking some notes.

If you follow these pieces of advice, your speaking and writing will improve automatically, and you can be sure that with a little effort they will become perfect.

【1】According to the author, which should you improve first among the four skills?

A. Reading and listening. B. Reading and writing.

C. Writing and speaking. D. Speaking and listening.

【2】To improve your reading, when you read you should .

A. look up all the new words in the dictionary

B. think about what you are reading actively

C. spend more time studying grammar

D. copy as many words and sentences as possible

【3】The author seems to agree with the view that .

A. everyone should listen to VOA or BBC programs every day

B. you needn’t practice listening if you keep on reading every day

C. being good at reading is helpful in improving your listening

D. you should take notes of whatever you are hearing

【4】The passage is mainly about how to .

A. choose suitable listening materials

B. deal with new words in reading

C. improve your English as quickly as possible

D. become fluent in speaking and writing English

【题目】请认真阅读下列短文，并根据所读内容在文章后表格中的空格里填入一个词。注意：每个空格只填1个单词。

Aspirin

Aspirin (acetylsalicylic acid) has been used for many years as a painkiller. It also has an anti-inflammatory (消炎) action and can be used to reduce fever. Aspirin is already recommended for people to prevent stroke and heart attack because it improves one's blood circulation. So many people already take daily aspirin as a heart drug. Although aspirin can cause deadly internal bleeding, which is relatively rare, its benefits for people are great, not only to help increase the length of people's lives, but to prevent and treat cancer, or to stop cancer spread according to the latest research.

Taking a low dose (剂量) of aspirin every day can prevent and Rothwell, from Oxford University, and his colleagues, who carried out the latest work, had already linked aspirin with a lower risk of certain cancers, particularly bowel（肠） cancer. But their previous work suggested people needed to take the drug for about 10 years to get any protection. Now the protective effect occurs much sooner—within three to five years—based on a new analysis of data from 51 trials involving more than 77,000 patients. And aspirin appears not only to reduce the risk of developing many different cancers in the first place, but may also stop cancers spreading around the body.

Taking a low (75 — 300mg) daily dose of aspirin appeared to cut the total number of cancer cases by 25 % after only three years—there were nine cancer cases per 1,000 each year in the aspirin-taking group, compared with 12 per 1,000 for those taking dummy pills. It also reduced the risk of a cancer death by 15% within five years (and sooner if the dose was higher than 300mg). And if patients stayed on aspirin for longer, their cancer death risk went down even further—by 37% after five years.

Low-dose aspirin also appeared to reduce the probability that cancers, particularly bowel, would spread to other parts of the body, and by as much as half in some instances. However, Prof. Rothwell says for most fit and healthy people, the most important things they can do to reduce their lifetime cancer risk is to give up smoking, take exercise and have a healthy diet.

But experts warn that there is still not enough proof to recommend it to prevent cancer cases and deaths and warn that the drug can cause dangerous side effects like stomach bleeding. Prof. Peter Johnson of Cancer Research UK, along with other experts, said it was still a good idea that people thinking of taking aspirin should first consult their doctors because of the possible side effect. And people should get some decisive advice from the government as to whether aspirin should be recommended more widely and the government should also advise the public about the benefits and risks of aspirin.

Aspirin

Functions

To reduce fever

To 【1】 Pains

To prevent stroke and 【2】 attack

【3】 effect

To cause cause deadly internal 【4】

Fresh

evidences

To cut the total number of cancer cases by 【5】

To 【6】 the risk of certain cancers within five years and of a cancer death by 15% within five years and by 37% after five years.

To make it 【7】 to prevent the spread of cancer

【8】 opinion

People should discuss with their doctors 【9】 taking aspirin.

The public should be 【10】 about the benefits and risks of aspirin.

【题目】请回答下列问题：

（1）细胞膜主要由 组成，还有少量的 。

（2）功能越复杂的细胞膜，蛋白质的 越多。

（3）植物传粉后，同种和不同种花粉都会落在雌蕊柱头上，同种花粉粒能萌发，不同种花粉粒一般不能萌发，这与细胞间相互识别有关，细胞识别体现了细胞膜的 功能。

（4）植物细胞在细胞膜外面还有一层 ，它的主要化学成分是 ，对植物细胞有 作用。

【题目】七选五

根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

Recently some American scientists have given a useful piece of advice to people in industrialized nations. They say people should eat more of the same kind of food eaten by humans living more than 10,000 years ago. 1

The scientists say that the human life has changed greatly. Our bodies have not been able to deal with these changes in lifestyle and this had led to new kinds of sicknesses. 2 So they are called “diseases of civilization”. Many cancers and diseases of the blood system are examples of such diseases.

Scientists noted that people in both the Old Stone Age and the New Stone Age enjoyed very little alcohol or tobacco, probably none. 3 However, a change in food is one of the main differences between life in ancient times and that of today.

Stone Age people hunted wild animals for their meat, which had much less fat than domestic ones. They ate a lot of fresh wild vegetables and fruits. They did not have milk or any other dairy products, and they made very little use of grains. 4 We eat six times more salt than our ancestors. We eat more sugar. We eat twice as much fat but only one third as much protein and much less vitamin C.

5 But scientists say that we would be much healthier if we eat much the same way the ancient people did, cutting the amount of fatty, salty and sweet food.

A. Stone Age people lived a simple life.

But today, we enjoy eating a lot of these.

C. In that case, they would live much healthier.

D. Ancient people also got lots of physical exercise.

E. These new sicknesses were not known in ancient times.

F. People today probably don’t want to live like our ancestors.

G. Modern people used to suffer from “diseases of civilization”.

【题目】完成句子

1. 不管情况如何，我都会相信你所说的。

________ ________ ________ ________， I will believe what you said.(however)

2. 我们的女主人使我们都感觉像在家里一样。

Our hostess ________ ________ ________ ________ ________ ________？(make)

3. 买票之后我们走进了戏院。

________ ________ ________ ________， we went into the theatre.(buy)

4. 他向加油站驶去。

He ________ ________ ________ ________ the filling station.(make)

5. 我们正要出发突然下起雨来。

We ________ ________ ________ ________ when it began to rain.(start)

6. 由于没有上课，他们昨天去公园了。

________ ________ ________ ________， they went to the park yesterday.(there)

7. 这座村庄在战乱中被烧毁了。

This village ________ ________ ________ ________ ________ during the war.

8. —八点钟在电影院外(见面)怎么样？

—How about eight o'clock outside the cinema?

—这正好适合我。

—________ ________ ________ ________.

9. 我希望被委派到那所新学校教学。

I hope ________ ________ ________ ________ the new school to teach.

10. 低着头，他走进教室。

He walked into the classroom, ________ ________ ________(lower)．

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