单选题 A Health Profile A health profile is a portrait of all of the factors that influence your health. To draw your health profile, you will {{U}} {{U}} 1 {{/U}} {{/U}}what diseases run in your family, what health hazards you may be exposed to {{U}} {{U}} 2 {{/U}} {{/U}}work, how your daily {{U}} {{U}} 3 {{/U}} {{/U}}compares to the recommended standards, how much time per week you {{U}} {{U}} 4 {{/U}} {{/U}}exercising and what type of exercise you engage {{U}} {{U}} 5 {{/U}} {{/U}}, how stressful your work and family environments are, what kinds of illnesses you get regularly, and {{U}} {{U}} 6 {{/U}} {{/U}}or not you have any one of a number of addictions. {{U}} {{U}} 7 {{/U}} {{/U}}this portrait, your should have a checkup to determine how your blood, heart, and lungs are functioning. This checkup will serve {{U}} {{U}} 8 {{/U}} {{/U}}a baseline, to which you can then compare later tests. {{U}} {{U}} 9 {{/U}} {{/U}}this profile is thoroughly drawn, you can begin to think about setting health priorities based {{U}} {{U}} 10 {{/U}} {{/U}}your particular portrait. For example, if you drink two martinis every evening, have a high-stress {{U}} {{U}} 11 {{/U}} {{/U}}, are overweight, smoke a pack of cigarettes a day, and use marijuana occasionally on weekends, you should quit smoking first, followed {{U}} {{U}} 12 {{/U}} {{/U}}losing the excess weight, reducing the stress of your job, giving up your marijuana habit, and then finally giving some {{U}} {{U}} 13 {{/U}} {{/U}}to those martinis if you want to prevent first cancer, and then heart disease. Even for the youthful working person who has never been sick a day in his life, who is {{U}} {{U}} 14 {{/U}} {{/U}}excellent health, a good look at all health habits and at work and home environments may suggest changes that will {{U}} {{U}} 15 {{/U}} {{/U}}him in the future.

单选题We need to extract the relevant financial data.

单选题Radioactive Wastes One of the major problems of nuclear energy is the inability of scientists to discover a safe way to dispose of the radioactive wastes which occur throughout the nuclear process. Many of these wastes remain dangerously active for tens of thousands of years, while others have a life span closer to a quarter of a million years. Various methods have been used to date, but all have revealed weaknesses, forcing scientists to continue their search. The nuclear process involves several stages, with the danger of radioactivity constantly present. Fuel for nuclear reactors comes from uranium ore (铀矿石), which, when mined, spontaneously produces radioactive substances as by-products. This characteristic of uranium ore went undetected for a long time, resulting in the deaths, due to cancer, of hundreds of uranium miners. The United States attempted to bury much of its radioactive waste material in containers made of steel covered in concrete and capable of holding a million gallons. For a long time it was believed that the nuclear waste problem had been solved, until some of these tanks leaked, allowing the radioactive wastes to seep into the environment. Canada presently stores its nuclear waste in underwater tanks, with the long-term effects largely unknown. However, plans are under consideration for above-ground storage of spent fuel from reactors. These plans include the building of three vast concrete containers, which would be two stories high and approximately the length and width of two football fields. Other suggestions include enclosing the waste in glass blocks and storing them in underground caverns, or placing hot containers in the Antarctic region, where they would melt the ice, thereby sinking down about a mile. This idea has since been abandoned because of the possible adverse effect on the ice sheets.

单选题Hurricane Katrina A hurricane is a fiercely powerful, rotating form of tropical storm that can be 124 to 1,240 miles in diameter. The term hurricane is derived from Hurican, the name of a native American storm god. Hurricanes are typical of a calm central region of low pressure between 12 to 60 miles in diameter, known as the eye. They occur in tropical regions. Over its lifetime, one of these storms can release as much energy as 10,000 nuclear bombs. The seed for hurricane formation is a cluster of thunderstorms over warm tropical waters. Hurricanes can only form and be fed when the sea-surface temperature exceeds 27℃ and the surrounding atmosphere is calm. These requirements are met between June and November in the northern hemisphere. Under these conditions, large quantities of water evaporate and condense into clouds and rain—releasing heat in the process. It is this heat energy, combined with the rotation of the Earth that drives a hurricane. When the warm column of air from the sea surface first begins to rise, it causes an area of low pressure. This in turn creates wind as air is drawn into the area. This spinning wind drags up more moisture-laden air from the sea surface in a process that swells the storm. Cold air falls back to the ocean surface through the eye and on the outside of the storm. Initially, when wind speeds reach 23 miles per hour, these mild, wet and grey weather systems are known as depressions. Hurricane Katrina formed in this way over the south- eastern Bahamas on 23 August 2005. Katrina has had a devastating impact on the Gulf Coast of the US, leaving a disaster zone of 90, 000 square miles in its wake—almost the size of the UK. Thousands have been killed or injured and more than half a million people have been displaced in a humanitarian crisis of a scale not seen in the US since the great depression. The cost of the damage may top $100 billion.

单选题New Brain Cells Love to Learn Wisdom in old age depends on a fresh supply of new brain cells, a study in mice suggests. When mature mice learn a new task, their newly generated brain cells are three times more active than their old ones, the researchers found. The findings add to a growing body of evidence that the adult brain needs a steady addition of new cells to maintain its mental faculties. Paul Frankland at the Hospital for Sick Children in Toronto, Ontario, Canada, and colleagues injected a group of mice with a chemical agent that stains only those cells born in the animals' brains at the time of injection. One week later, the team taught some of the mice how to navigate through a maze (迷宫), before sacrificing them to analyse the cells in a region of the brain called the hippocampus(海马体),which is key to learning and memory. In stages, the rest of the mice also underwent this paired process of learning and hippocampal examination at increasing time intervals from the initial injection. Frankland's team analysed the mice's stained hippocampal cells for key proteins—evidence that the cells were active and forming the new neural connections vital for learning. The team found that the stained cells had undergone significantly more activity in the mice that had learned the maze soon after the injection-when the stained cells were newly generated. For example, those that had learned the maze six weeks after the injection had three times as much "activity" in their stained cells as those mice that learned the maze eight weeks after injection, when the stained cells were fully mature. Cells examined at less than six weeks' old at the time of learning did not show as much activity as at six weeks, however. According to Frankland, this suggests that when neurons reach six weeks of age they are specifically recruited to form the brain networks that support new memories. "The results strengthen the link between new cells in the adult brain and learning-and shows more convincingly that they have a functional role," Frankland says. He believes the study is the first to provide positive evidence that newly generated brain cells are more active than old ones.

单选题For many years my uncle ran a very Usuccessful/U engineering business.

单选题Sounds can be called a language only when they have a structure and a grammar.

单选题I am in favor of his plan because it is reasonable.A. rejectB. acceptC. chooseD. support

单选题There was a {{U}}simultaneous{{/U}} trial taking place in the next build.

单选题Many cinemagoers were Ustunned/U by the film's violent and tragic end.

单选题Due to the effect of alcohol, your thought and your mouth will not coordinate properly.

单选题All the pupils seem to be very Ucheerful/U.

单选题A red flag was placed there as a token of danger.

单选题Our lives are intimately bound up with theirs.

单选题It seems {{U}}highly{{/U}} unlikely that she will pass the exam. A. very B. completely C. usually D. mostly

单选题He was elevated to the post of prime minister.

单选题Henry"s news report covering the conference was so comprehensive that nothing had been omitted.

单选题The basic model of A3XX can carry more than 500 passengers.

单选题The price of a 29-inch television has decreased by 30%.