Acids are chemical compounds that, in water solution, have a sharp taste, a corrosive action on met——青夏教育精英家教网—

摘要： Acids are chemical compounds that, in water solution, have a sharp taste, a corrosive action on metals, and the ability to turn certain blue vegetable dyes red. 酸是一种化合物.它在溶于水时具有强烈的气味和对金属的腐蚀性.并且能够使某些蓝色植物染料变红.

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阅读理解

　　Women with an hour glass figure have brains to go with their curves(曲线), scientists claim．

　　Going in at the waist is said to be a sign of intelligence which leads to brighter children, too, Wonmen such as Nigella Lawson with a big difference between thir waist and hip measurements scored significantly better in tests than those with thinner, straighter frames, Researchers concluded that it was not necessary for a woman to be skinny-what mattered was that her waist should be smaller than her hips, A ratio of 3∶5 was found to be idea,

　　The study, by the Universities of Pittsdburgh and California, involved 16,000 women and girls, According to the scientists, the results are no mere quirk of nature．They claim that the fat Around culvy hips and thighs(大腿)holds higher levels of-3 fatty acids which are essential for the growth of the brain during pregnancy．The fat which collects around the waist, howover．is more likely to contain-6 fatty acids, which areless suited to brain growth．

　　Reporting in the joumal Evolution and Human Behaviour, the researchers found that the children of curvy mothers are more likely to do well in cognitive tests than others．they claim that this could help explain why the children of teenage mothers．who might not yet be physically mature enough to have developed real curves-tend to do less well in school．

　　As wel las boosting(提升)brainpower－3 fatty acids found in oily fish arc considered to be of huge health benefit Although the study analysed women's bodies only－3 fatty acids are also stored in men's hips, However it is not known whether men with wide hips benefit from the same brain power boost．

(1)

Which shows the possible shape of an hour glass?
[　　]
A．
B．
C．
D．

(2)

Suppose the following measurements are taken from four women．Which of them is more likely to have bright children?
[　　]
A．	Waist：60 cm; Hip：100 cm
B．	Waist：60 cm：Hip：80 cm
C．	Waist：55 cm; Hip 160 cm
D．	Waist：120 cm; Hip：110 cm

(3)

The underlined sentence‘the results are nomere quirkofnature,’possible tells us the results ________．
[　　]
A．	can be explained scientifically
B．	are strange and hard to explain
C．	have just come about by chance
D．	are very interesting

(4)

According to the researchers, teenage mothers tend to have less bright children because ________．
[　　]
A．	they aren't so good at child care
B．	they usually have less fat than mature women
C．	they area't physically strong enough
D．	their waist and hip measurements differ less

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　　话题链接：Proper habits of nutrition can be developed by paying attention to the variety of foods included in the diet; and the quantity of each kind of food eaten．A diet, or the food regularly eaten, must contain all the nutritional(营养的)elements．Different food contains different vitamins(维生素)，let's look at the food one by one．

　　EGGS

　　Eggs are an excellent source of complete protein(蛋白质)；they contain all essential amino acids(氨基酸)．One large egg contains 7 or 8 grams of first-class protein．Also found in eggs are vitamins A, B2, D, and E; niacin(烟酸)；copper; iron; phosphorus(磷)；and unsaturated(不饱和的)fats．The egg yolk contains the richest known source of choline, found in lecithin and necessary for keeping the cholesterol (胆固醇)within the egg emulsified(蛋白)．The egg yolk also contains biotin(维生素H)，one of the B-complex vitamins．

　　FIBER

　　Fiber is the part of food that is not digested by the human body, such as the skin of an apple and the husk(壳，皮)of a wheat kernel．The normal functioning of the intestinal tract depends upon the presence of adequate fiber．A low-fiber diet has been associated with heart disease, cancer of the colon and rectum(直肠)，diverticulosis(瘢痕形成)，varicose veins(纹理)，phlebitis(静脉炎)，and obesity．

　　FISH

　　Fish are excellent sources of high-grade protein, polyunsaturated fatty acids, and minerals, especially iodine(碘)and potassium(钾)．Fish are categorized as freshwater fish, saltwater fish, and shellfish．These types differ slightly in nutritive value．Freshwater fish provide magnesium(镁)，phosphorus, iron, and copper．Saltwater fish and shellfish are rich in iodine, fluorine(氟)，and cobalt (钴)．Fatty fish, such as halibut(比目鱼)，mackerel(鲭鱼)，and salmon, are good sources of vitamins A and D．Herring, oysters, and sardines contain vanadium and zinc．Shellfish are low fatty acids but are relatively high in cholesterol．

　　FRUITS

　　Fresh fruits are good sources of vitamins and minerals, especially vitamin A and C, carbohydrates in the form of cellulose and natural sugars, and water．They are good substitutes of such high-carbohydrate(碳水化合物)foods as candy, cookies, and cakes, which contain few nutrients．Yellow fruits, such as apricots, cantaloupe(香瓜)，and persimmons(柿子)，are good sources of carotene(胡萝卜素)，which is converted to vitamin A．Aside from acerola cherries and rose hips, the best natural sources of vitamin C are the citrus fruits, such as oranges, grapefruit, lemons, and tangerines(橘)；other sources of vitamin C are cantaloupe, strawberries, and tomatoes．Apples and bananas contain valuable bulk fiber in the form of indigestible(不可吸收的)cellulose, which is needed for regular bowel movement．Bananas are high in magnesium(镁)and may be useful for treatment of diarrhea, colitis, ulcers, and certain cases of protein allergies．Bananas and pears are the highest in natural sugars．

　　GRAINS

　　Grains are often referred to as cereals ;they are the seeds of various grasses such as wheat, oats, rice, and barley．Often called the “staff of life”, they provide the bulk of the world's food supply．Common foods made from these grains are flours, breads, breakfast cereals, and macaroni．

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想一想：Healthy eating is the essential thing for the physical and mental development for human being．But the eating habit of our Chinese people is not very reasonable or suitable．If you are responsible for the improvement of the Chinese healthy eating, what will you do to change the formed eating habit of Chinese people?

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Many rivers are ________ with chemical waste from factories．

polluting

destroying

destroyed

polluted

阅读理解

　　Metals usually occur (发生,出现) in nature as minerals(矿石). At present, about 80 different metals are known to man. But with so many metals to choose from the question arises: which metal shall we use? Is there any metal that is “best for everything”? Of course not. For example, iron is strong but it rusts easily, while gold, one of the first metals found by man, does not rust at all. Should we use gold, therefore, to build fences? Imagine the cost of a fence made of gold! It’s important to consider the cost and the supply (提供)of a metal. Also, when we choose a metal for a certain job, we examine its physical properties. Is it strong enough to be used as a support for a bridge? Can it he used in a telephone to conduct (传导) electncity? Is it light enough to be used in an air plane wing? Can it he drawn out to make a fine wire? We also examine its chemical properties. Will it resist acid (酸) ? Is it too active to use? Is it easy to combine [ (使)结合] with other elements? Each use must be studied carefully. Then we can choose the right kind of metal, or combinations(结合)of metals.

　　The metals used for constructing buildings, cars, planes and ships must he strong and easy to form by casing, machining, and cutting. These metals are called structural(生锈)metals. The two most important structural (结构的) metals are iron (steel) and aluminum. Aluminum, which is much lighter than iron, has made possible the modem aviation (航空) industry.

　　Very few of the metal things we use in industry and every day life are made of a single pure metal. Most of them are combinations of metals called alloys (合金). Alloys are formed when two or more metals are melted together and allowed to cool and harden. It has been known for a long time that when some metals are combined in this way, the alloy takes on new physical properties (性质). The use of alloy makes it possible to manufacture (制造) many articles which must have special properties. Nowadays, if an inventor cannot find a metal that suits his purpose, he tries to have a new alloy made that will. The search for new alloys is going on all the time.

1．Metals are usually ________.

[　　]

A．best for everything

B．made use of in daily life in pure forms

C．found in nature as minerals

D．in the same quality

2．________ According to the text, uses of metals depend on their ________.

[　　]

3．The properties most important to a structural are its ________.

[　　]

A．lightness and activity

B．electric conductivity and heat conductivity

C．strength and easiness of shaping

D．resistance to acids and capability of being bent

4．A combination of two or more metals is called ________.

[　　]

5．The characteristic of alloy is ________.

[　　]

A．new chemical properties

B．new physical properties

C．special ways of formation

D．rarity

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For many years, scientists couldn't figure out how atoms and molecules on the Earth combined to make living things. Plants, fish, dinosaurs, and people are made of atoms and molecules, but they are put together in a more complicated way than the molecules in the primitive ocean. What's more, living things have energy and can reproduce, while the chemicals on the Earth 4 billion years ago were lifeless.
　　After years of study, scientists figured out that living things, including human bodies, are basically made of amino acids and nucleotide bases. These are molecules with millions of hydrogen, carbon, nitrogen, and oxygen atoms. How could such complicated molecules have been formed in the primitive soup? Scientists were stumped.
　　Then, in 1953, two scientists named Harold Urey and Stanley L. Miller did a very simple experiment to find out what had happened on the Primitive Earth. They set up some tubes and bottles in a closed loop, and put in some of the same gases that were present in the atmosphere 4 billion years ago: water vapor, ammonia, carbon dioxide, methane, and hydrogen.
　　Then they shot an electric spark through the gases to simulate bolts of lightning on the ancient Earth, circulated the gases through some water, sent them back for more sparks, and so on. After seven days, the water that the gases had been bubbling through had turned brown. Some new chemicals were dissolved in it. When Miller and Urey analyzed the liquid, they found that it contained amino acids-the very kind of molecules found in all living things.
61. When did scientists come to realize how the atoms and molecules on the Earth combined to make living thing?
　　A. 4 billion years ago. B.1953.　C. After seven days.D. Many years later.
62. Scientists figured out that human bodies are basically made of .
A.amino acids
B.molecules
C. hydrogen, carbon, nitrogen and oxygen atoms
D. water vapor, ammonia, carbon dioxide, methane and hydrogen
63. Harold Urey and Stanley L.Miller did their experiment in order to .　
A. find out what had happened on the Earth 4 billion years ago
　　 B.simulate bolts of lightning on the ancient Earth
　　 C. dissolve some new chemicals
　　D.analyze a liquid
64. At the end of the last paragraph, the underlined word "it" refers to .
A. a closed loop   B. an electric spark   C.water   D. the liquid
65. According to the writer, living things on the Earth include .
　A. atoms and molecules                     B.chemicals　
C. plants, fish, dinosaurs and human beings     D.the primitive soup

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