1UnitUnit 5 5 FirstFirst aidaid .阅读理解A A(2018广西师大附属外校高三模拟)Every day, people come into contact with thousands of chemicals. These chemicals are said to be harmless to human health. In fact, the chemicals are considered so safe that we wash with them. We put them on our bodies and even our faces. Other chemical products are used throughout our homes.By the time you walk out of your front door, you have already been exposed to thousands of chemicals. On its own, each chemical seems harmless. But in combination with other chemicals, they may become deadly. That is the finding of a twoyear study by a highprofile(高调的) task force of scientists. The task force was told to investigate the cancercausing possibility of chemical mixtures.Linda Gulliver was one of the 174 scientists on the task force. Their job was to study the cancercausing potential of 85 chemicals. All 85 are said to be common in the environment.Ms Gulliver explains that chemicals have the potential or ability to form dangerous mixtures. Even simple minerals can become dangerous when mixed with chemicals found in plastics or beauty products.Working in groups, the scientists explored how different chemical mixtures could lead to cancer. Ms Gullivers team looked at the ability of different combinations to support the increase of malignant(恶性的) human cells.She says the current way to identify whether chemicals cause cancer is to test them one at a time. This method leads, she adds, to a long list of supposedly “safe” chemicals. She and her team say that approach needs to change.“We definitely need certain researchto find out what mixtures of chemicals would be more harmful than others; what groups of chemicals, when together, would produce more harmful effects. And at the moment, that is not known.”An estimated one in five cancers has been linked to chemical exposure. It may turn out that the cancercausing villain(恶棍) is not a single chemical at all.2语篇导读本文为科普说明文，揭示了多种安全的化学物质相混或成致癌物。1What effect may one single chemical have on us according to the text?AIt may destroy our body. BIt may not cause danger to us.CIt may let us suffer from cancer. DIt may let our body make a change.解析 B B 细节理解题。根据第三段第一句可知，一种化学物质可能不会对我们造成危害，故选 B 项。2What can we learn about Ms Gullivers research?AShe has found 85 cancercausing chemicals.BShe has found reasons for five kinds of cancers.CShe has found that only one chemical can cause cancer.DShe is not sure what mixtures of chemicals are more harmful.解析 D D 细节理解题。根据倒数第二段可知，格利佛也不确定哪一种化学物质的混合物更具危害，故选 D 项。3According to the text, we can infer that the study _. Ais just wasting time and money Bis still in need of great effortsCwill cause panic in public Dwill be resisted by the public 解析 B B 推理判断题。根据倒数第二段可以推知，这项研究仍需要很大的努力，故选B 项。4What is the best title for the text?AMixtures of Safe Chemicals May Cause CancerBBeing Exposed to One Chemical Is DangerousCHow Mixtures of Safe Chemicals Come into Being？DWhat Is the Real Cause for Cancer?解析 A A 标题归纳题。根据全文尤其是最后一段最后一句可知，文章主要揭示了多种安全的化学物质相混可能会形成致癌物，故选 A 项。B B(状元桥原创)Many birds may be small, but theyre great natural athletes. Every year, birds literally cross mountains, deserts and seas to reach their favorite breeding(繁殖) and feeding grounds. Arctic ternseach weighing about a fifth of a poundmigrate halfway around the world, flying to Greenland in spring and the South Pole in winter. Birds rarely go “as the crow flies”in a direct line from Point A to Point B So, how do they choose their routes?Answering this question sheds light on whats likely a driving force in 3birds evolution. Migration can be risky business, which means those migratory routes that have survived to this day likely have major benefits for those that take them, even if they might seem circuitous(迂回的) at first glance. Bird biologists have already figured out a few factors that make certain, longer routes better for birds, including avoiding the open ocean, and having safe rest stops along the way. Now, a new study offers evidence that birds consider annual wind patterns too. Together, these factors make certain paths appealing to birds of many kinds, creating the worlds great migratory flyways.To check the effect of wind on migratory routes, biologists created a mathematical model of more than a million potential migration routes, all around the world. They added 21 years worth of worldwide wind data into the model. They then compared how long it would take a bird to fly between pairs of points around the world if the bird took the shortest route, versus the windoptimized (风向最佳的) route. Wind optimization could reduce the time it takes to migrate between places, the researchers found. Its important to remember that a bird doesnt actually plan its migration. It may follow what it learned from its parents. A bird cant be able to predict what winds will blow over its route.语篇导读本文为说明文。每年，大量的鸟儿都会从一个地方迁徙到另一个地方，下面且看它们是如何选择迁徙线路的。5Why does the writer mention “Arctic terns” in the firs