高考英语阅读理解二轮限时训练精品题(2)及答案

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2014高考英语阅读理解二轮限时训练精品题(2)及答案【2014高考英语南京市、盐城市一模】请认真阅读下列短文,从短文后各题所给的A、B、C、D四个选项中,选出最佳选项,并在答题卡上将该项涂黑。

For decades, public health officials have puzzled over a surprising fact about HIV: Only about 10-20 percent of infants who are breastfed by infected mothers catch the virus. Tests show, though, that HIV is indeed present in breast milk, so these children are exposed to the virus multiple times daily for the first several months of their lives.Now, a group of scientists and doctors from Duke University has figured out why these babies don’t get infected. Human breast milk naturally contains a protein called Tenascin C that neutralizes HIV and, in most cases, prevents it from being passed from mother to child. Eventually, they say, the protein could potentially be valuable as an HIV-fighting tool for both infants and adults that are either HIV-positive or at risk of contracting the infection.The research, published in Proceedings of the National Academy of Sciences, was inspired by previous work by other researchers showing that, both in tissue cultures (组织培养) and live mice, breast milk from HIV-negativemothers was naturally endowed with HIV-fighting properties. Scientists suggested that a few different proteins in the milk could potentially be responsible, but no one knew which one.As part of the study, the researchers divided breast milk into smaller fractions (部分) made up of specific proteins via a number of filters (过滤) — separating the proteins by size, electrical charge and other characteristics—and tested which of these fractions, when added to a tissue culture, prevented the cells from being infected by HIV. Eventually, they found that one particular protein was present in all the HIV-resistant fractions but in none of the others: Tenascin C.Tenascin C works by blocking a key protein on HIV’s envel ope that normally ties up to a receptor on a T cell’s membrane called CCR5. In doing so, Tenascin C prevents HIV from mixing with the T cell and injecting its RNA inside.Still, the researchers say that other natural elements in milk might play a role in fighting HIV as well. “It’s clearly not the whole story, because we do have samples that have low amounts of this protein but still have HIV-neutralizing activity,” the study’s lead author Permar says.“So itmay be acting in concert with other antiviral an d antimicrobial factors in the milk.”Whatever those other factors are, though, the finding vindicates (证明……的正确) recent changes to UN guidelines that recommend even HIV-positive mothers in resource-poor countries should breastfeed, if they’re taking anti-retroviral drugs to combat their own infection.The next steps, Permar says, are determining which area of Tenascin C is active and whether it can effectively prevent transmission in a live animal. If it works, it could potentially be incorporated (合并) into an HIV drug with broader applications. It’s even possible that it could someday be adapted to reduce the risk of HIV transmission in adults as well as infants.63. What is the main idea of Paragraph 1?A. The breast milk from an infected mother doesn’t contain HIV at all.B. It’s less likely for infants feeding on infected mothers’ breast milk to catch HIV.C. The possibilities of infants catching HIV have nothing to do with infected mothers.D. Children breastfed by infected mothers won’t catch HIV though exposed to it frequently.64. Why did the researchers divide breast milk into smaller fractions?A. To find out Tenascin C.B. To make up specific proteins.C. To add them to a tissue culture.D. To test what prevents cells being infected.65. Which of the following about Tenascin C is true?A. It has become an effective tool in fighting HIV.B. It was first found by Permar and her research group.C. It can prevent transmission in a live animal effectively.D. It can sometimes prevent mother-to-child transmission of HIV.66. What can we know about Permar and her research group according to the passage?A. They have found a cure for HIV.B. They have helped change UN guidelines.C. They will do more researches on Tenascin C.D. Their finding is based on their previous work.【参考答案】63. B 64. D 65. D 66. C阅读下列短文,从每题所给的A、B、C和D项中,选出最佳选项,并在答题卡上将该项涂黑。

Abraham Lincoln was born into poverty 200 years ago. At any other time and place, this lowly origin would have dictated his future, but in Lincoln’s case, his self-determination and force of will made it possible for him to secure his seat in his country's history. He has become a role model in the self-made America.If you want to learn about somebody who didn’t quit, look no further. Abraham Lincoln had two business ventures failed, and the second one made him bankrupt, so he had to spend the next 17 years of his life paying for the debt. He also lost 8 different elections. It seemed that he had never done things right at the first time: the f i r s t time he ran for state legislature for Congress, for land officer, for Senate, all of these failed, and the first time he sought the vice-presidential nomination, he got less than 100 votes nationally. But he never found it too shameful to carry on his mission. Then later in 1860, on such a rough road, he made it to the White House. He lived up to his famous saying, “Always bear in mind that your own determination to success is more important than any other.”He could have quit many times-—-but he didn’t and because he didn’t quit,he became one of the greatest presidents in the history of America. One important way Lincoln influences present society is that we look back on his life as a role model for future generations. Lincoln’s high character influences us because we compare present-day politicians to the example Lincoln set. A major influence Lincoln has on the united States today is simply through the good example he set when it came to honesty, persistence and leadership.36.According to the first paragraph, which of the following statements is true?A. Lincoln was born with a silver spoon in his mouth.B. Like Lincoln, a poor origin leads to a bright future.C. America is considered self-made because of Lincoln.D. Self-determination and will contributed to Lincoln’s success.【答案】D【解析】细节理解题。