Drug companies have spent billions of dollars...

Drug companies have spent billions of dollars searching for therapies to reverse or significantly slow Alzheimer’s disease, but in vain. Some researchers argue that the best way to make progress is to create better animal models for research, and several teams are now developing mice that more closely imitate how the disease destroys people’s brains.

The US National Institutes of Health (NIH), the UK Dementia Research Institute and Jackson Laboratory (JAX) - one of the world’s biggest suppliers of lab mice - are among the groups trying to genetically design more suitable mice. Scientists are also exploring the complex web of mutations(突变) that influences neurological(神经学的) decline in mice and people.

“We appreciate that the models we had were insufficient. I think it’s sort of at a critical moment right now.” says Bruce Lamb, a neuro-scientist at Indiana University who directs the NIH-funded programme.

Alzheimer’s is marked by cognitive impairment(认知损伤) and the build-up of amyloid-protein plaques(淀粉样蛋白块) in the brains of people, but the disease does not occur naturally in mice. Scientists get around this by studying mice that have been genetically modified to produce high levels of human amyloid protein. These mice develop plaques in their brains, but they still do not display the memory problems seen in people.

Many experimental drugs that have successfully removed plaques from mouse brains have not lessened the symptoms of Alzheimer’s disease in people. One focused stumble came last month, when three companies reported that their Alzheimer’s drugs had failed in large, late-stage clinical trials. Although the drugs successfully blocked the accumulation of amyloid protein in mice, they seemed to worsen cognitive decline and brain shrinkage in people.

The drive for better mouse models comes as genomics studies are linking the most common form of Alzheimer’s to dozens of different genes. This diversity suggests that each case of the disease is caused by a different combination of genetic and environmental factors. “There is no single Alzheimer’s disease,” says Gareth Howell, a neuro-scientist at Jackson Laboratory (JAX) in Bar Harbor, Maine.

Howell argues that scientists’ reliance on lab mice with only a few genetically engineered mutations might have limited research. His own work suggests that in mice, just as in people, genetic diversity plays a part in determining how Alzheimer’s develops.

1.What do you know about the lab mice used for the Alzheimer’s research from the text?

A.The lab mice also display the memory problems.

B.Suitable lab mice are fundamental to the research.

C.Mice with Alzheimer’s disease suffer from mutations.

D.Drugs have been invented to slow Alzheimer’s disease.

2.From paragraph 5, we can know that the experimental drugs “__________”.

A.functioned well in large, early-stage clinical trials

B.fail to make people get rid of the relevant symptoms

C.successfully prevent people forming amyloid protein

D.worsen cognitive decline and brain shrinkage in mice

3.What does Gareth Howell think of Alzheimer’s?

A.It is various genes that count in the development of Alzheimer’s.

B.The increasingly polluted environment contributes to Alzheimer’s.

C.The most common form of Alzheimer’s is the drive for better mice.

D.It is caused by the accumulation of amyloid-protein plaques in people.

4.Which of the following could be the best title for the passage?

A.Experimental drugs successfully reverse Alzheimer’s

B.The real causes of Alzheimer’s have been confirmed

C.Alzheimer’s is the biggest memory killer in the aged

D.Frustrated Alzheimer’s researchers seek better lab mice

高二英语阅读理解中等难度题查看答案及解析

Does it make sense for countries to invest billions of dollars in space programs when millions of people in their country are living below the poverty line? Many people ask this question and I almost tire of answering it.

Let's talk about Duchenne Muscular Dystrophy (DMD) first. This is a terrible disease in which the victims progressively lose the ability to control their body. It affects almost only boys and shows itself when the boys are around age 5. They're wheelchair-bound by age 12, and will be dead before their 30th birthday. There is no cure. However, there are treatments. They're based on crystalline (晶体) protein structures, whose formation is adversely (不利地) affected by the presence of Earth's constant unidirectional (单一方向的) gravitational field. However, according to a study conducted by the Japan Aerospace Exploration Agency (JAXA) on the International Space Station (ISS), crystalline protein structures form regularly in microgravity conditions, which allows for targeted drugs designed to "double these boys' life spans (寿命)".

And you want to talk about feeding the hungry? We have space lettuce (生菜).And it's structurally and nutritionally equivalent to Earth lettuce. Space is pretty much everything there is, which means you can make a lot of lettuce in space. In fact, one of the potential growth markets in lunar colonization (月球殖民) is food trade. Food can be mass produced and sent to Earth to feed the hungry. By the way, as far as I am concerned, as for feeding the hungry, food distribution is the issue rather than food supply.

Space exploration is one of the best things that humanity has ever done.

1.What do people want to know by asking the question in Paragraph 1?

A.Whether there is a cure for DMD.

B.How many people live below the poverty line.

C.How much money is spent on space programs.

D.Whether space programs benefit people on Earth.

2.What can be learned about DMD?

A.It seems to spare girls.

B.Its cure lies in the ISS.

C.It gets serious in microgravity conditions.

D.Its patients need wheelchairs their entire life.

3.What is the author's attitude to growing food in space?

A.Doubtful. B.Positive.

C.Disapproving. D.Uncaring.

4.The text is most probably taken from a ________.

A.website to buy and sell the newest space products

B.website to ask questions and get quality answers

C.legal document

D.science fiction

高二英语阅读理解困难题查看答案及解析

UNICEF is appealing for more than one billion dollars in aid for women and children around the world．The United Nations Children's Fund has released its " Humanitarian Action Report" for two thousand ten． The report lists twenty -eight countries and territories with some of the world's most pressing crisis affecting women and children．

Haiti was considered to be in crisis long before the earthquake in January．The deputy executive director of UNICEF, Hilde Johnson, says the quake has only made the need for aid more immediate．But she says children all over the world have the right to the same assistance as children everywhere else．

The "Humanitarian Action Report" discusses several issues that UNICEF says increasingly threaten the basic rights of women and children．It says climate change has caused droughts and' food insecurity in many areas．High food prices and the global financial crisis of two thousand eight - two thousand nine have only added to poverty and malnutrition （ 营养不良）．And armed conflict continues to threaten the lives of millions．

Hilde Johnson says children are always the most affected by conflicts and disasters．They face an increased risk of abuse, including sexual violence and other serious rights violations （侵犯）．

UNICEF deals with about two hundred emergencies around the world every year．The greatest need last year was in sub - Saharan Africa．The report says drought, food insecurity and civil unrest affected about twenty - four million people．

Violence and displacements（ 驱逐）of people were especially bad in Sudan, Chad, the Democratic Republic of Congo and the Central African Republic．

In Asia, UNICEF expects its financial assistance needs to more than double this year．This is partly the result of adding Pakistan and the Philippines to the latest report．In Pakistan, it says, more than two million people have been forced from their homes by the conflict in the．Swat Valley and other areas of the northwest．And in the Philippines, more than two hundred thousand people are still living in shelters after severe storms last year．

This years UNICEF report talks about the value of public and private partnerships in helping children and families in emergencies．

And thats the VOA Special English Development Report, written by June Simms．For a link to the UNICEF report listing the twenty - eight countries and territories in crisis, go to www.unsv.com．I'm Steve Ember．

1.According to Hilde Johnson,  the most easily affected persons suffering from conflicts and disasters are __________．

A．women                     B．children                    C．the old                      D．the disabled

2.From this passage we know that the most serious problems in Asia are __________．

A．earthquakes and malnutrition

B．displacements and storms

C．sexual violence and other rights violations

D．droughts and food insecurity

3.Which of the following might serve as a suitable title for this passage?

A．Haiti was in crisis due to the earthquake in January

B．Violence in the twenty -eight countries and territories

C．UNICEF Appeals for Aid for Women and Children

D．the value of public and private partnerships in helping

高二英语阅读理解简单题查看答案及解析

2010 was a good year for American farmers. They earned about eighty-two billion dollars. That is almost one-third more than that they earned last year. And it is twenty-six percent higher than the ten-year average. Values for grain and oilseed crops are up about three percent from last year. The value of animal production is up by almost seven percent.

In 2011, farm exports are expected to break the all-time high set in 2008.The Agriculture Department says exports in 2011 could top one hundred and twenty-six billion dollars. The largest buyer of agricultural products is expected to be Canada. But farm exports to China are predicted to come within five hundred million dollars of Canadian purchases. Secretary Vilsack says countries in Southeast Asia and the Middle East are also buying more from American farmers.

Poor growing conditions overseas played an important part in higher prices for American crops in 2010.Charlotte Hebe brand is chief executive of the International Food and Agricultural Trade Policy Council in Washington. She said drought(干旱)conditions had a big effect over the summer. She said,“There were horrible weather problems, not just in Russia but also in some of the other former Soviet Union countries.”

Wheat prices rose after Russia stopped wheat exports,although Russia later eased the ban(禁令).“Wheat used to be America’s top crop. What’s interesting,though,is that wheat production has actually become less over the past few years because corn has become the most popular crop,”said economist Charlotte Hebebrand.

Corn is mostly fed to animals. But Miss Hebebrand said with the recent increase in wheat prices, American farmers might plant more wheat again. Corn and wheat are the two largest crops supported by the government.

1.We know that compared to 2009,in 2010 American farmers——.

2.What does the Agriculture Department expect in 2011?

3.What is implied in Paragraph 3?

4.We can infer that in the past few years American farmers——

5.According to what Miss Hebebrand said, we know American farmers will ——

高二英语阅读理解困难题查看答案及解析

If you want to disturb the car industry, you’d better have a few billion dollars: Mom-and-pop carmakers are unlikely to beat the biggest car companies. But in agriculture, small farmers can get the best of the major players. By connecting directly with customers, and by responding quickly to changes in the markets as well as in the ecosystems(生态系统), small farmers can keep one step ahead of the big guys. As the co-founder of the National Young Farmers Coalition (NYFC, 美国青年农会) and a family farmer myself, I have a front-row seat to the innovations among small farmers that are transforming the industry.

For example, take the Quick Cut Greens Harvester, a tool developed just a couple of years ago by a young farmer, Jonathan Dysinger, in Tennessee, with a small loan from a local Slow Money group. It enables small-scale farmers to harvest 175 pounds of green vegetables per hour—a huge improvement over harvesting just a few dozen pounds by hand—suddenly making it possible for the little guys to compete with large farms of California. Before the tool came out, small farmers couldn’t touch the price per pound offered by California farms. But now, with the combination of a better price point and a generally fresher product, they can stay in business.

The sustainable success of small farmers, though, won’t happen without fundamental changes to the industry. One crucial factor is secure access to land. Competition from investors, developers, and established large farmers makes owning one’s own land unattainable for many new farmers. From 2004 to 2013, agricultural land values doubled, and they continue to rise in many regions.

Another challenge for more than a million of the most qualified farm workers and managers is a non-existent path to citizenship — the greatest barrier to building a farm of their own. With farmers over the age of 65 outnumbering(多于) farmers younger than 35 by six to one, and with two-thirds of the nation’s farmland in need of a new farmer, we must clear the path for talented people willing to grow the nation’s food.

There are solutions that could light a path toward a more sustainable and fair farm economy, but farmers can’t clumsily put them together before us. We at the NYFC need broad support as we urge Congress to increase farmland conservation, as we push for immigration reform, and as we seek policies that will ensure the success of a diverse and ambitious next generation of farmers from all backgrounds. With a new farm bill to be debated in Congress, consumers must take a stand with young farmers.

1.The author mentions car industry at the beginning of the passage to introduce 　　　　　　 .

A. the progress made in car industry　　 B. the importance of investing in car industry

C. a trend of development in agriculture　　 D. a special feature of agriculture

2.What does the author want to illustrate with the example in paragraph 2?

A. Small farmers may gain some advantages over big ones.

B. Loans to small local farmers are necessary.

C. Technology is vital for agricultural development.

D. Competition between small and big farms is fierce.

3.What is the difficulty for those new farmers?

A. To gain more financial aid.　　 B. To hire good farm managers.

C. To have farms of their own.　　 D. To win old farmers’ support.

4.What should farmers do for a more sustainable and fair farm economy?

A. Invest more to improve technology.　　 B. Expand farmland conservation.

C. Become members of NYFC.　　 D. Seek support beyond NYFC.

高二英语阅读理解困难题查看答案及解析

For more than twenty years scientists have been searching for signs of life on other planets. Most of these searches have been done over the radio. The hope is that someone in outer space may be trying to get in touch with us. Scientists also have sent radio and television messages on spaceships traveling through space, on the chance that someone may be receptive （善于接受的） to such messages.

Scientists are using powerful radio telescope to listen to signals from about 1,000 stars, all within 100 light years of earth. In addition, they will scan (扫视) the entire sky to “listen” for radio messages from more distant stars. Using a computer, they will be able to monitor more than eight channels at one time. Scientists are looking for any signal that stands out from the background noise.

Of the 200 billion stars in the Milky Way galaxy （银河星系）, scientists find that five percent are like our sun. Perhaps half of them have a planet like earth. Such a planet would be a reasonable distance from the star for temperatures to be right for the evolution of life. Based on the inhabitable (that can be lived in) planets in our galaxy, most scientists agree that chances are likely that one or more of these planets support some life.

However, many scientists wonder whether intelligent （有智力的） life exists on other planets. Some believe that twenty years of searching without any intelligible （可理解的） messages shows that no one is out there. They say that the evolution of intelligence comparable to ours is unlikely.

Other scientists believe that our search hasn’t been long enough to rule out the possibility that intelligent life exists in our galaxy. Although our sun family in only about five billion years old,　 our galaxy is about 20 billions years old. In that time, some scientists think it is likely that civilizations are much more advanced than ours. Perhaps these civilizations send us no signals; perhaps we have not recognized the signals they have sent us. If we hope to find intelligent life, these scientists believe that we have to keep looking.

1.According to the passage, how many planets in our galaxy might human beings live?

A. 5 billion　　 B. 10 billion　　 C. 15 billion　　 D. 200 billion

2.The first paragraph in this passage is mainly about ______.

A. where scientists are looking for signs of life on other planets

B. why scientists are looking for signs of life on other planets

C. how scientists are looking for signs of life on other planets

D. when scientists are looking for signs of life on other planets

3. The underlined word “monitor” in the passage means “______”.

A. find　　 B. follow　　 C. study　　 D. form

4. Which of the statements is TRUE based on the information in the passage?

A. The earth is one of the oldest planets in our galaxy.

B. Most scientists believe that there is intelligent life on other planet.

C. Scientists don’t believe that there might be life on other planets.

D. Scientists are trying different ways to find signs of life on other planet.

高二英语阅读理解中等难度题查看答案及解析

For more than twenty years scientists have been searching for signs of life on other planets. Most of these searches have been done over the radio. The hope is that someone in outer space may be trying to get in touch with us. Scientists also have sent radio and television messages on spaceships travelling through space, on the chance that someone may be receptive to such message.

　Scientists are using powerful radio telescopes to listen to signals from about 1,000 stars, all within 100 light years of Earth. In addition, they will scan the entire sky to "listen" for radio messages from more distant stars. Using a computer, they will be able to monitor more than eight channels at one time. Scientists are looking for any signal that stands out from the background noise.

　Of the 200 billion stars in the Milky Way galaxy, scientists find that five percent are like our sun. Perhaps half of them have a planet like Earth. Such a planet would be a reasonable distance from the star for temperatures to be right for the evolution (进化) of life. Based on the inhabitable (可居住的) planets in our galaxy, most scientists agree that chances are likely that one or more of these planets support some life.

　However, many scientists wonder whether intelligent life exists on other planets. Some believe that twenty years of searching without any intelligible messages shows that no one is out there. They say that the evolution of intelligence comparable to ours is unlikely.

Other scientists believe that our search hasn’t been long enough to rule out the possibility that intelligent life exists in our galaxy. Although our sun family is only about five billion years old, our galaxy is about 20 billion years old. In that time, some scientists think it is likely that civilization much more advanced than ours have developed. Perhaps these civilizations send us no signals; perhaps we have not recognized the signals they have sent us. If we hope to find intelligent life, these scientists believe that we have to keep looking.

1.According to the passage, how many planets in our galaxy might be inhabitable?

A. 5 billion         B. 10 billion           C. 15 billion           D. 200 billion

2.The first paragraph in this passage is mainly about __________.

A. how scientists are looking for signs of life on other planets

B. why scientists are looking for signs of life on other planets

C. where scientists are looking for signs of life on other planets

D. When scientists are looking for signs of life on other planets

3.The underlined word “monitor” in Paragraph two means “__________”.

A. find              B. follow            C. check           D. form

4.Which of the following is TRUE based on the information in the passage?

A. The earth is the oldest planet in our galaxy.

B. All scientists believe that there is intelligent life on other planets.

C. Scientists are trying different ways to find signs of life on other planets.

D. Scientists will give up the search for signs of life on other planets.

高二英语阅读理解中等难度题查看答案及解析

For decades developed countries have poured large quantities of dollars into developing countries through foreign aid. Some people think that aid from developed countries to developing countries is not having the desired effect. 1.. They argue that foreign aid makes developing countries lazy to develop for themselves. They also argue that a lot of these aids have conditions attached, which enables developed countries to reap (收获) from developing countries more than they sow. As a Hungarian economist once said, “Aid money is money taken from the poor in developed countries and given to the rich in developing countries.”

2.. In their opinion, even though foreign aid isn’t having the desired result, it is better than not providing aid at all. “Over half of the world’s population lives in less developed countries.”

Many of them are rather poor. “3.,” said one volunteer in Africa. They argue that most 5developing countries still need aid before they move away from dependency to self-reliance.

4.. However, it is also true that there are certain things which foreign aid can’t do. Experience has shown that foreign aid can’t solve every economic problem of a developing country. It can’t bring about instant progress. 5.. If we really want to help those less developed countries, we need to seriously consider the types of aid we are sending over there.

A.I do believe that no one should be doing nothing

B.Foreign aid may not produce large economic benefits

C.Many other people, however, are against the arguments above

D.Thus, foreign aid is of little importance in promoting development

E.It is true that aid plays an economically useful role in poor countries

F.A country’s economic development depends, eventually, upon its own people

G.In certain cases, foreign aid to developing countries is causing more harm than good

高二英语七选五中等难度题查看答案及解析

Dogs have a very good____ of smell and are often used to search for survivors in an earthquake.

A. sense       B. manner     C. means     D. idea

高二英语单项填空中等难度题查看答案及解析

Mr. Li was out of touch last week. The police ________ for him since.

A. have been searching　　　　 B. were searching

C. had searched　　　 　　　　 D. has searched

高二英语单项填空中等难度题查看答案及解析