______ the cold, thin air and low oxygen leve...

______ the cold, thin air and low oxygen levels also can cause mountain sickness.

A. Regardless of　　 B. Apart from　　 C. In addition　　 D. Except for

高三英语单项填空中等难度题查看答案及解析

______ the cold, thin air and low oxygen levels also can cause mountain sickness.

高三英语单项填空中等难度题查看答案及解析

Vitamin D helps bones and muscles grow strong and healthy．Low levels of vitamin D can lead to diseases such as rickets(软骨病), mainly found in children．The thinning of bone is a common problem as people, especially women, get older．

But more and more research is suggesting that vitamin D might also help prevent many diseases．The easiest way to get vitamin D is from sunlight．The sun’s ultraviolet(紫外线的)rays react with skin cells to produce vitamin D．But many people worry about getting skin cancer and skin damage from the sun．As a result they stay out of the sun．Also, darker-skinned people produce less vitamin D than lighter-skinned people．The amount also de-creases in older people and those living in northern areas that get less sunlight．

Not many foods naturally contain vitamin D．Foods high in this vitamin include oily fish and fish liver oils．Farmed fish have only about one-fourth as much vitamin D as wild fish．Small amounts of vitamin D are found in beef liver, cheese and egg yolks．But most of the vitamin D in the American diet comes from foods such as milk．

Research in the last several years has shown that low levels of vitamin D may increase the risk of heart attacks in men and deaths from some cancers．More doctors are now having their patients tested for their vitamin D levels．But as research continues, some experts worry that if people take too much vitamin D, it might act as a poison, Also, skin doctors warn people be careful with sun exposures because of the risk of skin cancer．

1.The first paragraph is mainly about________．

A．the muscle diseases                        B．the sources of vitamins

C．the importance of health                    D．the functions of vitamin D

2.Which of the following people produce the least amount of vitamin D?

A．Elderly darker-skinned people．

B．Young lighter-skinned people．

C．Elderly lighter-skinned people．

D．Young darker-skinned people．

3.People can get the most vitamin D from________．

A．beef liver           B．cheese               C．wild fish           D．farmed fish

4.What can we infer from the text?

A．Being exposed to sunlight is the safest way to get vitamin D

B．Lack of vitamin D can make people age quickly

C．Proper vitamin D levels people need are still not determined now．

D．The vitamin D level is higher in men than in women．

高三英语阅读理解中等难度题查看答案及解析

____ can be seen in the chart right here, the air pollution level in the city has been increasing over the last months.

A. What         B. It            C. that          D. As

高三英语单项填空中等难度题查看答案及解析

You can’t be ______ when you camp _____ an high altitude, where the air is thin.

A. enough careful; at B. too careful; at C. careful enough; on  D. too careful; on

高三英语单项填空中等难度题查看答案及解析

When the weather gets cold, we can put on more clothes, stay next to a fireplace, turn on the air conditioner or simply travel to a warmer city to spend the winter – people have many different ways of coping with the cold.

But things are not as easy for plants. Unlike humans, plants can’t move to escape the cold or generate heat to keep themselves warm. So how do they manage to survive the freezing winter?

It turns out that plants have their own strategies too, said a study published on Dec 22 in the journal Nature.

According to researcher Amy Zanne of George Washington University, US, the cold is a big challenge for plants. Their living tissues can be damaged when they freeze. “It’s like a plant’s equivalent to frostbite (冻疮),” Zanne told Science Daily. Also, the process of freezing and thawing (解冻) can cause air bubbles to form in the plant’s water transport system. “If enough of these air bubbles come together as water thaws they can block the flow of water from the roots to the leaves and kill the plant,” she explained.

To live through cold weather, plants have developed three traits, according to the study. Some plants, such as oak trees, avoid freezing damage by dropping their leaves before the winter chill sets in – effectively shutting off the flow of water between roots and leaves – and growing new leaves and water transport cells when the warm spring returns.

Other plants, pine trees for example, protect themselves by narrowing their water transport cells, which makes it easier for cells to travel among air bubbles.

The third strategy is also the most extreme – some plants die on the ground in winter and start growing as new plants from seeds when conditions get warmer.

However, the study also found that these smart strategies were developed very slowly – over millions of years of evolution. This leads scientists to worry that plants may not be able to deal with human-caused climate change, which has only started occurring over the past few decades.

Scientists are hoping that this study can help people find possible ways to save plants from the threat of climate change.

1.What is the article mainly about?

A.Why plants are not afraid of the winter chill.

B.The ways that plants survive cold weather.

C.Changes in plants’ water transport system in winter.

D.How plants evolve to keep up with climate change.

2.According to the article, if a plant freezes in the winter, ______.

A.it produces more living tissues to stay alive

B.its leaves quickly fall out and its roots begin to die

C.its water transport cells are narrowed

D.its water transport system could be blocked

3.How do oak trees usually survive the cold winters?

A.By dropping their leaves before winter.

B.By narrowing their water transport cells.

C.By widening their water transport cells.

D.By dropping seeds on the ground so that the new trees can grow in the spring.

4.What are scientists worried about when it comes to plants according to the article?

A.Plants may not be able to adapt to the increasingly cold climate.

B.Human activities might have a great impact on the pace of plants’ evolution.

C.Plants may not be able to evolve fast enough to adapt to human-caused climate change.

D.The strategies plants develop are not good enough to protect them against cold.

高三英语阅读理解中等难度题查看答案及解析

Shoppers are also less likely to queue for long if the item they are buying is of low value, and ____ food and drink shopkeepers are having to find new ways to deliver good customer service.

A. in the end          B. after all        C. as a result   D. on the contrary

高三英语单项填空困难题查看答案及解析

Cold weather during winter months may keep many people from leaving home and running in the open air.

However, a new study shows that the drop in temperature is a good reason to run. In fact, researchers say, running in cold weather helps improve one’s performance.

Many people say running in the winter can be difficult. Two reasons are the low temperatures and bitter winds. Yet many runners might find it easier than running in hot weather.

That could be because lower temperatures reduce stress on the body. When you run in cold weather, your heart rate and the body’s dehydration (脱水) levels are lower than in warmer conditions. The body needs less water on a cold day than in warm weather.

This information comes from sports scientists at St. Mary’s University in London. John Brewer is a professor of applied sport science at St. Mary’s.

For this study, he and other researchers put a group of people into a room they called an “environmental chamber.” The researchers then recreated summer and winter weather conditions in the room. The test subjects were asked to run 10,000 meters under both conditions. Brewer says he and his team recorded biological measurements of the runners.

“We’ve got a group of subjects into the environmental chamber, we’ve changed the conditions to replicate the summer or winter and we’ve got them to run a 10km under both of those conditions and taken various measurements on each runner while they’ve been completing their 10km.”

Brewer says every movement runners make produces heat. He explains that one way in which we lose heat is by sweating. The body loses heat through droplets of sweat. He says the body also loses heat by transporting the blood to the surface of the skin.

1.What can we know about running in winter?

A. It increases pressure of the body.　　 B. It improves the function of body.

C. It makes your heart rate higher.　　 D. It needs more water than in summer.

2.What can we know about the research according to the text?

A. Researchers interviewed the subjects

B. Subjects were asked to run in winter and summer.

C. Subjects built the “environmental chamber”.

D. Biological measurements of the runners were recorded.

3.Which of the following can replace the underlined word “replicate” in Paragraph 7?

A. Combine.　　 B. Remember.

C. Copy.　　 D. Decorate.

4.What’s the best title for the passage?

A. Environmental Chamber　　 B. The Way of Losing Heat

C. Running in Cold Weather Improves Performance　　 D. Biological Measurements of the Runners

高三英语阅读理解中等难度题查看答案及解析

Cold weather during winter months may keep many people from leaving home and running in the open air. However, a new study shows that the drop in temperature is a good reason to run. 1.

Many people say running in winter can be difficult. Two reasons are the low temperatures and bitter winds.2.That could be because lower temperatures reduce stress on the body. When you run in cold weather, your heart rate and the body's dehydration (脱水) levels are lower than in warmer conditions. 3.

This information comes from John Brewer, who is a professor of applied sport science at St. Mary’s. For this study, he and other researchers put a group of people into a room they called an "environmental chamber". The researchers then recreated summer and winter weather conditions in the room.4.Brewer says he and his team recorded biological measurements of the runners.

He says that the most important thing for people who run in cold conditions is to wear the right clothing. Wear gloves on your hands.5.And especially wear more than one layer of clothing to keep sweat away from your skin.

A.Yet many runners might find it easier than running in hot weather.

B. We have good reasons to run in winter.

C. Wear shoes that will keep you from falling.

D. Many feel nervous when running in the cold weather.

E. The body needs less water on a cold day than in warm weather.

F. In fact, running in cold weather helps improve one’s performance.

G. The test subjects were asked to run 10,000 meters under both conditions.

高三英语七选五中等难度题查看答案及解析

A decade-long study, also the first major research into air pollution and disease has shown that living near a main road increases the risk of dementia(痴呆). The study of 6.6 million people found that one in 10 dementia deaths in people living within 50 metres of a busy road was due to waste gas and noise.

Air pollution is already known to contribute to the deaths of around 40,000 people in Britain each year by worsening breathing and heart conditions, while previous research showed emissions (排放物) can cause brain shrinkage. But the new study by Canadian public health scientists is the first to find a link between living close to heavy traffic and the increasing of dementia, a discovery described as "believable" and "impressive" by British experts.

Dr Hong Chen said. "Our study suggests that busy roads could be a source of environmental stressors that could give rise to the onset of dementia. Population growth and urbanization has placed many people close to heavy traffic, and with widespread exposure to heavy traffic and growing rates of dementia, even a modest effect from near-road exposure could cause a large public health burden.  More research to understanding this link is needed, particularly into the effects of different aspects of traffic, such as air pollutants and noise."

In the new study, the team tracked all adults aged between 20 and 85 living in Ontario for more than a decade from 2001 to 2012. They used postcodes to determine how close people lived to a main road and analyzed medical records to see if they went on to develop dementia, Parkinson's disease or multiple sclerosis(多发性硬化).

While there was no correlation between living near a road and Parkinson's disease or multiple sclerosis, dementia risk reduced as people lived further from a main road, with a 7 percent higher risk in developing dementia among those living within 50 metres; a 4 percent higher risk at 50-100 metres and a 2 percent higher risk at 101-200 metres. After 200 metres there was no increase. Researchers believe that noise of traffic may also play a role in the raised risk as well as other urban pollution, which is often present near busy roads.

1.What can we know about Canadian's new study?

A. British experts think highly of it.

B. It brings benefits to dementia patients.

C. It shows that air production is very serious.

D. It shows that air pollution can cause brain shrinkage.

2.What Dr Hong Chen said showed that______.

A. people are diagnosed with dementia mainly due to air pollution

B. widespread exposure to traffic will reduce the risk of having dementia

C. the link between living near roads and having dementia was not obvious

D. busy roads could be a source of environmental stressors that caused dementia to increase

3.What does the underlined the word ‘correlation’ mean?

A. Change.　　 B. Improvement.

C. Association.　　 D. Secret

4.What can be inferred from the last paragraph?

A. Living near a main road adds to the risk of noise.

B. Living beyond 300 metres of a main road is safe for people.

C. Living within 200 metres of a main road has a lower risk of having dementia.

D. The further people live away from heavy traffic, the smaller the risk of having dementia.

高三英语阅读理解中等难度题查看答案及解析