单选题 Each year, millions of people in Bangladesh drink ground water that has been polluted by naturally high levels of arsenic poison. Finding safe drinking water in that country can be a problem. However, International Development Enterprises has a low-cost answer. This non-governmental organization has developed technology to harvest rainwater. People around the world have been harvesting rainwater for centuries. It is a safe, dependable source of drinking water. Unlike ground water, rainwater contains no minerals or salts and is free of chemical treatments. Best of all, it is free. The rainwater harvesting system created by International Development Enterprises uses pipes to collect water from the tops of buildings. The pipes stretch from the tops of buildings to a two-meter tall storage tank made of metal. At the top of the tank is a so-called "first-flush" device made of wire screen. This barrier prevents dirt and leaves in the water from falling inside the tank. A fitted cover sits over the "first-flush" device. It protects the water inside the tank from evaporating. The cover also prevents mosquito insects from laying eggs in the water. Inside the tank is a low coat plastic bag that collects the water. The bag sits inside another plastic bag similar to those used to hold grains. The two bags are supported inside the metal tank. All total, the water storage system can hold up to three-thousand-five-hundred liters of water. International Development Enterprises says the inner bags may need to be replaced every two to three years. However, if the bags are not damaged by sunlight, they could last even longer. International Development Enterprises says the water harvesting system should be built on a raised structure to prevent insects from eating into it at the bottom. The total cost to build this rainwater harvesting system is about forty dollars. However, International Development Enterprises expects the price to drop over time. The group says one tank can provide a family of five with enough rainwater to survive a five-month dry season.

单选题The child was so Uingenuous/U that even when she knocked the television off its stand so that it was irreparably damaged, her parents thought her to be charming.

单选题Which of the following is NOT mentioned as a factor shaping personality?

单选题There is a real possibility that we could finish the task ahead of schedule, ______ enough time.

单选题(While) smoking was associated with an attention of weight gain among black adults, (no such effect) occurred among white men or women, the latter (was) the group (most likely) to smoke for weight control.

单选题Some weeks ago, riding in a cab from Boston to Cambridge, my driver turned and asked me what I did for a living. "Teach English," I said. "Is that so?" The young man continued. "I was an English major." But then, instead of chatting idly about Joyce or dropping the subject altogether, this driver caught me short. "You guys," he said, turning back so that his furry face pressed into the glass partition, "ought to be shot." I think he meant it. The guilty party in this present state of affairs is not really the academic discipline. It is not the fault of English and philosophy and biology that engineering and accounting and computer science afford students better job opportunities and increased flexibility in career choice. Literature and an understanding of, say, man's evolutionary past are as important as ever. They simply are no longer perceived in today's market as salable. That is a harsh economic fact. And it is not only true in the United States. Employment prospects for liberal arts graduates in Canada, for example, are said to be the worst since the 1930s. What to do? I think it would be shortsighted for colleges and universities to advise students against majoring in certain subjects that do not appear linked (at least directly) to careers. Where our energies should be directed instead is toward the development of educational programs that combine course sequences in the liberal arts with course in the viable professions. Double majors--one for enrichment, one for earning one's bread--have never been promoted very seriously in our institutions of higher learning, mainly because liberal arts and professional-vocational faculties have long been suspicious or contemptuous of one another. Thus students have been directed to one path or the other, to the disadvantage of both students and faculty. A hopeful cue could be taken, it seems to me, from new attempts in the health profession (nursing and pharmacy, for example), where jobs are still plentiful, to give the humanities and social sciences a greater share of the curriculum. Why could not the traditional history major in the college of arts and sciences be pointed toward additional courses in the business school, or to engineering, or to physical therapy? This strategy requires a new commitment from both the institution and the student and demands a much harder look at the allocation of time and resources. But in an age of adversity, double majors are one way liberal arts students can more effectively prepare for the world outside.

单选题Inductive reasoning involves making useful generalization about the environment as a whole , based on a necessarily limited number of observations. As so , it is an important tool that people use to build the models of reality they need to function effectively. While conclusions can be wrong if observations are faulty or are drawn from an unrepresentative sample, if properly used, it can be incredibly powerful.

单选题His desire to ______ other people has caused trouble in his family.

单选题Dolphins' brains are particularly well-developed to ______.

单选题Questions 21—23 are based on a report about obesity. You now have 15 seconds to read Questions 21—23.

单选题Diamonds have little______value and their price depends almost entirely on their scarcity.(2011年四川大学考博试题)

单选题Scientists created ultra fine films of specialized crystals by means of ______.

单选题Yet it's easy to ______ on fat without changing your diet completely or giving up all your favorite foods.

单选题Different cultures are more prone to ______ certain illnesses because of the food that is characteristic in these cultures. A. contract B. conduct C. confine D. conquer

单选题His parents ______ him to enlist when he was seventeen.

单选题When the nurse took his temperature, it was three degrees above______.

单选题As my examinations are coming next week, I'll take advantage of the weekend to ______on some reading.

单选题Mrs. White has been living in town for only one year, but she seems to be ______ with everyone who comes to the store.