摘要:9.The new medicine the spread of the disease. A.arrested B.improved C.kept D.supported 解析:句意:“这种新药阻止了这种疾病的传播. 考查arrest即“阻止 .keep...from...是阻止.B.D不合语境. 答案:A

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The Atlantic Ocean is one of the oceans that separate the Old World from the New. For centuries it kept the Americans from being discovered by the people of Europe.

Many wrong ideas about the Atlantic made early sailors unwilling to sail far out into it. One idea was that it reached out to “the edge of the world.” Sailors were afraid that they might sail right off the earth. Another idea was that at the equator the ocean would be boiling hot.

The Atlantic Ocean is only half as big as the Pacific, but it is still very large. It is more than 4,000 miles (6,000km) wide where Columbus crossed it. Even at its narrowest it is about 2,000 miles (3,200km) wide.

Two things make the Atlantic Ocean rather unusual. For so large an ocean it has very few islands. Also, it is the world’s saltiest ocean.

There is so much water in the Atlantic that it is hard to imagine how much there is. But suppose no more rain fell into it and no more water was brought to it by rivers. It would take the ocean about 4,000 years to dry up. On the average the water is a little more than two miles (3.2km) deep, but in places it is much deeper. The deepest spot is near Puerto Rico. This “deep” measures 30,246 feet-almost six miles (9.6km).

One of the longest mountain ranges of the world rises from the floor of the Atlantic. This mountain range runs north and south down the middle of the ocean. The tops of a few of the mountains reach up above the sea and make islands.

Several hundred miles eastward from Florida there is a part of the ocean called the Sargasso Sea. Here the water is quiet, for there is little wind. In the days of sailing vessels(船) the crew were afraid they would be becalmed(停滞不前) here. Sometimes they were.

Today the Atlantic is a great highway. It is not, however, always a smooth and safe one. Storms sweep across it and pile up great waves. Icebergs float down from the Far North across the paths of ships.

We now have such fast ways of traveling that this big ocean seems to have grown smaller. Columbus sailed for more than two months to cross it. A fast modern steamship can make the trip in less than four days. Airplanes fly from New York to London in only eight hours and from South America to Africa in four!

Which world is the Old World?

A. Africa               B. Europe                     C. Asia                  D. All of above

What caused people to be unwilling to explore the Atlantic?

A. There are no ships big enough to get across the Ocean.

B. Sailors were afraid of being lost in the Ocean.

C. The Atlantic Ocean was very unusual because it has few islands and the saltiest water.

D. Many incorrect ideas such as “the edge of the world”, “the equator with boiling hot water”, made people think the Ocean was full of danger.

What is the topic of the fifth paragraph?

A. How deep the water is

B. How to measure the water in the Atlantic Ocean

C. How much water the Ocean holds.

D. How rain affects the Ocean water.

We can learn from the text that ______.

A. the Atlantic is the largest ocean on earth

B. one of the longest mountain ranges lies in the Atlantic

C. the Atlantic has a lot of islands in it

D. sailing on the Atlantic Ocean is always quiet, smooth and safe

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Dorothea Shaw is 71 years old and nearly blind, and she chose to live alone far away from people. She lives in Belize — a county the size of Wales with a population only that of Swansea. Her home is at Gales Point, a tiny village which can be reached only by sea or air; after a 10-mile walk into the hills one finally reaches a piece of land and two small houses so hidden in the thick over-grown forest that only a handful of people know Dorothea is there.

She lives happily and totally alone – growing her vegetables, looking after her trees and dogs, cats and chickens. Once a month or so an old friend passes by with her food supplies and letters-usually including a letter from her sister in Scunthorpe and some bits of clothing from friends in Canada. Sometimes a local man will come and cut wood for her and a group of British soldiers will come across her and be greeted with the offer of a cup of coffee.

At night she lies in her tiny sleeping room with the dogs on the floor, the cats on the table near the typewriter and one of the hens settled down in a corner of the bookshelf, and listens for hours to any Spanish, English, German or French broadcasts she can find on her radio. Sometimes she gets lonely but most of the time the animals and the radio are company enough.

But recently the very things that she had tried to get free from so well have begun to catch up with her. The peace of the forest has been destroyed by the noise of earth-moving machines not many miles away. What she once only heard of distantly on the radio is now on her doorstep. Things began to change three years ago. The new main north-south road in Belize was cut through the forest only four or five miles away. “Now more people know I’m here.” She says. “I feel more and more uneasy each day.”

Dorothea’s small houses ________.   

A. are entirely surrounded by trees   

B. have always been her home

C. were built for just a few people   

D. are in a county with the same population as Wales

Dorothea lives in the tiny village because ________.

A. she doesn’t like living near people    B. she is too old to move

C. machines destroyed her home        D. there’s nowhere else for her to live

Dorothea doesn’t get lonely since she has _______ with her.

A. her sister   B. some animals     C. friends from Canada    D. a postman

Dorothea spends a lot of time __________.

A. growing all the food she needs         B. cutting down trees

C. listening to the radio                 D. studying languages

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Can people change their skin colour without suffering like pop king Michael Jackson? Perhaps yes. Scientists have found the gene that determines skin colour.

The gene comes in two versions, one of which is found in 99 per cent of Europeans. The other is found in 93 to 100 per cent of Africans, researchers at Pennsylvania State University report in the latest issue of Science.

Scientists have changed the colour of a dark-striped zebrafish to uniform gold by inserting a version of the pigment(色素) gene into a young fish. As with humans, zebrafish skin colour is determined by pigment cells, which contain melanosomes(黑色素). The number, size and darkness of melanosomes per pigment cell determines skin colour.

It appears that, like the golden zebrafish, light-skinned Europeans also have a mutation(变异) in the gene for melanosome production. This results in less pigmented skin.

However, Keith Cheng, leader of the research team, points out that the mutation is different in human and zebrafish genes.

Humans acquired dark skin in Africa about 1.5 million years ago to protect bodies from ultra-violet rays of the sun(太阳光紫外线), which can cause skin cancer.

But when modern humans leave Africa to live in northern latitudes, they need more sunlight on their skin to produce vitamin D. So the related gene changes, according to Cheng.

Asians have the same version of the gene as Africans, so they probably acquired their light skin through the action of some other gene that affects skin colour, said Cheng.

The new discovery could lead to medical treatments for skin cancer. It also could lead to research into ways to change skin colour without damaging it like chemical treatment did on Michael Jackson.

51. The passage mainly tells us that ________.

  A. people can not change their skin colour without any pain

  B. the new discovery could lead to search into ways to change skin colour safely

  C. pop king Michael Jackson often changed his skin colour as he liked

  D. scientists have found out that people’s skin colour is determined by the gene

52. It can be inferred from the passage that ________.

  A. nowadays people who want to change their skin colour have to suffer a lot from the damage caused by the chemical  treatment

  B. Europeans and Africans have the same gene

  C. the new discovery could help to find medical treatments for skin cancer

  D. there are two kinds of genes

53. Scientists have done an experiment on a dark-striped zebra fish in order to ________.

  A. find the different genes of humans’

  B. prove the humans’ skin colour is determined by the pigment gene

  C. find out the reason why the Africans’ skin colour is dark

  D. find out the ways of changing peopl’s skin colour

54. The reason why Europeans are light-skinned is probably that ________.

  A. they are born light-skinned people

  B. light-skinned Europeans have mutation in the gen for melanosome production

  C. they have fewer activities outside

  D. they pay much attention to protecting their skin

55. The writer’s attitude towards the discovery is ________.

  A. neutral                      B. negative                   C. positive                    D. indifferent

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