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[主观题]

Many pure metals have little use because they are too soft, rust too easily, or have some

other ______ .

A．bruises

B．blunders

C．handicaps

D．drawbacks

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发布时间：2023-02-16

更多“Many pure metals have little use because they are too soft, rust too easily, or have some”相关的问题

第1题

Successful innovations have driven many older technologies to extinction and have resulted

in higher productivity, greater consumption of energy, increased demand for raw materials, accelerated flow of materials through the economy and increased quantities of metals and other substances in use per person. The history of industrial development is full of examples. In 1870, horses and mules were the prime source of power on U.S. farms. One horse or mule was required to support four human beings--a ratio that remained almost constant for many decades. At that time, had a national commission been asked to forecast the horse and mule population for 1970, its answer probably would have depended on whether its consultants were of an economic turn of mind. Had they been "economists", they would have recognized that the power of steam had already been harnessed to industry and to land and ocean transport. They would have recognized further that would be only a matter of time before steam would be the prime source of power on the farm. It would have been difficult for them to avoid the conclusion that the horse and mule population would decline rapidly.Which of the following is NOT mentioned by the author as a consequence of new technological developments？A.Older technologies die away.B.The quality of life is improved.C.Overall productivity increases.D.More raw materials become necessary.

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第2题

Successful innovations have driven many older technologies to extinction and have resulted

In 1870, horses and mules were the prime source of power on U. S. farms. One horse or mule was required to support four human beings—a ratio that remained almost constant for many decades. At that time, had a national commission been asked to forecast the horse and the population for 1970, its answer probably would have depended on whether its consultants were of an economic or technological turn of mind. Had they been "economists" , they would probably have projected the 1970 horse or mule population to be more than 50 million. Had they been "technologists", they would have recognized that the power of steam had already been harnessed to industry and to land and ocean transport. They would have recognized further that it would be the prime source of power on the farm. It would have been difficult for them to avoid the conclusion that the horse and mule population would decline rapidly.

According to the passage, what supplied most of the power on U. S. farms in 170？

A．Animals.

B．Humans.

C．Engines.

D．Water.

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第3题

A land free from destruction, plus wealth, natural resources, and labor supply--all these

were important factors, in helping England to become the center for the

Industrial Revolution. (31) they were not enough. Something else was needed to start the industrial process. That "something special" was men-- (32) individuals

who could invent machines, find new sources of power, and establish business organizations to reshape society. The men who (33) the machines of the Industrial Revolution came from many backgrounds and many occupations. Many of them were (34) inventors than scientists. A

man who is a pure scientist is primarily interested in doing his research (35) . He is not necessarily working so that his findings can be used. An inventor or one

interested in applied science is (36) trying to make something that has a concrete idea. He may try to solve a problem by using the theories (37) science or by

experimenting through trial and error. Regardless of his method, he is working to obtain a specific result: the construction of a harvesting machine, the burning of a

light bulb, or one of (38) other objectives. Most of the people who developed the machines of the Industrial Revolution were inventors, not trained scientists. A few were both scientists and inventors. Even

those who had (39) or no training in science might not have made their inventions if a groundwork had not been laid by scientists years (40) .A.ButB.AndC.Besides D.Even

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第4题

根据以下内容，回答下列各题。 In the old days, divers used to go down into the sea looking f

or ships that had sunk, because they hoped to find gold and jewels．Now divers still search for valuable things in sunken ships, but they also try to bring to the surface the ships themselves, or parts of them．The value of different kinds of metals has increased greatly over the last twenty or thirty years and even though a ship has been under the sea for many years, it may be worth a great deal． One famous sunken ship is the “Lusitania”, which sank off the southern coast of Ireland in 1915 with a loss of nearly, 1,500 lives．It has four huge propellers made of an expensive metal．Today each of those propellers is worth $ 300,000 or more．The ship lying on the sea-bed has been brought by a man called John Light．He paid about $ 1,200,000 for the whole ship．He hopes to bring up those propellers and sell them．He also hopes to sell other parts of the ship, when he has brought them to the surface, for about $ 600,000． Divers today try to bring to the surface _______．

A.gold and jewels

B.parts of ships

C.whole ships

D.all of the above

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第5题

When aluminum was first produced about a hundred and fifty years ago, it was so difficult

to separate from the ores(矿石) in which it was found that its price was higher than that of gold. The price remained high until a new process was discovered for refining the metal with the aid of electricity approximately three quarters of a century later. The new method was so much cheaper that aluminum became practical for many purposes, one of which was making pots and pans.

Aluminum is lightweight, rustproof and easily shaped into different forms. By mixing it with other metals, scientist have been able to produce a variety of alloys, some of which have the strength of steel but weigh only one third as much.

Today, the uses of aluminum are innumerable. Perhaps its most important use is in transportation. Aluminum is found in the engines of automobiles, in the hulls of boats. It is also used in many parts of airplanes. In fact, the huge "airbus" planes would probably never have been produced if aluminum did not exist. By making vehicles lighter in weight aluminum has greatly reduced the amount of fuel needed to move them. Aluminum is also being used extensively in the building industry in some countries.

Since aluminum is such a versatile(多用的) metal, it is fortunate that bauxite(铝土矿) , which is one of its chief sources, is also one of the earth's most plentiful substances. As the source of aluminum is almost inexhaustible, we can expect that more and more uses will be found for this versatile metal.

The price of aluminum was sharply reduced when people discovered a new refining process with the aid of______.

A．wind power

B．solar energy

C．hydraulic power

D．electricity

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第6题

It seems that beauty and women are twins. Observe for yourself. Ads on fashion flood TV sc

reen, radio programs, magazines and the streets. Whether they have realized or not, women are besieged (包围) by a sea of fashion. They are taught to think that without beautiful clothes they will grow old and lose their charm. So who dares to neglect dressing up at the cost of their appearance and youth？

But I do not agree with the opinion that women have to show their beauty through their looks. The richness of their mind proves to be more beautiful and attractive than their looks. A woman who has experienced many troubles and may be called "aunt" or "granny" can still maintain her beauty if she has such excellent qualities as knowledge, ability, a kind heart and concern for others.

In addition, old and young, beautiful and ugly are relative concepts. People who keep a young mind will never feel old. Curious about new things and eager to learn more, they keep up with the tide. Plainly dressed women may have a type of beauty, which is pure and real.

Reading and learning is the best way to keep one youthful. Good books are fertile soil which can feed the flower of one's heart and looks.

Why does the author say that beauty and women are twins？

A．Women are born to be beauties.

B．Women like to show off their beauties

C．Women are proud of their beauty

D．Women try to maintain their beauty by dressing up

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第7题

The word "Okay" is known and used by millions of people all over the world. Still, languag

e experts do not agree on where it came from.

Some say it came from the Indian peoples. When Europeans first came to America they heard hundreds of different Indian languages. Many were will developed.

One tribe especially had a well developed language. This was the Chocktaw tribe. They were farmers and fishermen whole lived in the rich Mississippi valley in what is now the state of Alabama. When problems arose, Chocktaw leaders discussed them with the tribal chief. They sat in a circle and listened to the wisdom of the chief.

He heard the different proposals, often raising and lowering his head in agreement, and saying, "Okeh," meaning "it is so."

The Indian languages have given many words to English. Twenty four of the American States almost half, have Indian names, Okalahoma, the Dakotas, Idaho, Wisconsin, Ohio and Tennessee, to name a few. And the names of many rivers, streams, mountains, cities and towns are Indian.

However, there are many people who dispute the idea that "Okay" came from the In di ans. Some say the President Andrew Jackson first used the word "Okay." Others claim the word was invented by John Jacob Astor, a fur trader of the late 1700s who became one of the world's richest men. Still others say a poor railroad clerk made up this word. His name was Obadiah Kelly and he put his initials(首写字母), O.K. on each package people gave him to ship by train.

So it goes, each story sounds reasonable and official.

But perhaps the most believable explanation is that the word "Okay" was invented by a political organization in the 1800s. Martin Van Buren was running for President. A group of people organized a club to support him. They called their political organization the "Okay Club. The letters "O" and "K" were taken from the name of Van Buren's hometown, the place where he was born, old Kinderhook, New York.

There is one thing about "Okay" that the experts do agree on: that the word is pure American and that it has spread to almost every country on earth.

There is something about the word that appeals to peoples of every language. Yet, here in America it is used mostly in speech, not in serious writing. In recent time, "Okay" has been given an official place in the English language. But it will be a long time before Americans will officially accept two expressions that come from "Okay." There are "Oke" and "Okeydoke".

______different opinions as where the word "Okay" came from are mentioned in the text.

A．Four

B．Five

C．six

D．Three

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第8题

Metals () when they are heated.

A.extend

B.enlarge

C.spread

D.expand