单选题Giving the child problems he cant solve will only frustrate him.

单选题There are four basic types of competition in business that form a continuum from pure competition through monopolistic competition and oligopoly (商品供应垄断) to monopoly. At one end of the continuum, pure competition results when every company has a similar product. Companies that deal in commodities such as wheat or corn are often involved in pure competition. In pure competition, it is often the ease and efficiency of distribution that influences purchase. In contrast, in monopolistic competition, several companies may compete for the sale of items that may be substituted. The classic example of monopolistic competition is coffee and tea. If the price of one is perceived as too high, consumers may begin to purchase the other. Coupons and other discounts (折扣) are often used as part of a marketing strategy to influence sales. Oligopoly occurs when a few companies dominate the sales of a product or service. For example, only five airline carriers control more than 70 percent of all ticket sales in the United States. In oligopoly, serious competition is not considered desirable because it would result in reduced revenue for every company in the group. Although price wars do occur, in which all companies offer substantial savings to customers, a somewhat similar tendency to raise prices simultaneously is also usual. Finally, monopoly occurs when only one firm sells the product. Some monopolies have been tolerated for producers of goods and services that have been considered basic or essential, including electricity and water. In these cases, it is government control, rather than competition, that protects and influences sales.

单选题States are considering major changes in prepaid college tuition programs - raising prices, restricting participation of canceling them - as they grapple with financial woes. Nationwide, families will likely have to pay more to participate, or accept that they might not cover tuition when children go to college. Colorado has closed its prepaid plan to new investors and told existing ones that it may not cover future tuition increases. Wisconsin stopped selling its plan Dec. 20. Maryland and Illinois are among states hiking prices by 20% or more. Prepaid plans let parents lock in tuition by paying for it now, protecting them against rising costs. But the hear market has hurt investment returns, leaving the plans unable to keep up with big increases in tuition. So far, Colorado is the only state that has told participants their investments may not cover tuition, and no plan has missed a payment. Other states have said they will fulfill obligations, even if it requires a legislative bailout. Still, the financial problems have forced thousands to grapple with uncertainty - something prepaid plans were designed to avoid. More than 1 million families have an estimated $ 8 billion invested in the plans, says ＜ Saving for College. com ＞. Some states, including Colorado, may replace the prepaid plan with a guaranteed investment contract, a CD-like investment that"s backed by an insurance company. Investors get a minimum rate of return, but no guarantee that it will cover tuition. Wisconsin"s EdVest program is encouraging investment in a stable value fund, which is similar to a guaranteed investment contract, in its investment plan. Wisconsin"s prepaid plan never guaranteed to cover tuition inflation. It also never got a lot of investors, possibly because it lacked that guarantee. In Florida, a task force is considering limiting the state"s prepaid program to low-income families. Ohio officials are also looking at limiting participation, but it"s a measure they hope to avoid. "Program administrators are looking for alternatives," says Andrea Feirstein, a state-plan consultant. Maryland recently boosted its prices by up to 30%; Illinois by up to 23%. The increases have made some prepaid plans uneconomical for parents of older children. In Ohio, the price of one year"s tuition for a child over 12 months old is $ 8, 000, more than 40% above current tuition at Ohio State. SO it may not be a good deal for children starting college in three or four years because tuition may not jump that much that fast.

单选题The change was so ______ that we hardly noticed it

单选题The judge said her case was ______, with no former cases to consult.

单选题Two or three days after the operation Bennett was beginning to feel______better.

单选题The tomato juice left brown______on the front of my jacket.

单选题It is not too late, but ______ action is needed. A. fight B. urgent C. hurry D. prompt

单选题He doesn't know much about politics, but he's always shooting off his mouth about how good he is. He is somewhat of a/an ______. A. dogmatist B. adventurer C. braggart D. humbler

单选题Squad members, already decked out in______chemical suits, put on masks and rubber gloves.

单选题If you ______ the bottle and cigarettes, you'll be much healthier.(2013年北京航空大学考博试题)

单选题The debate as to whether the Internet or books are a boon to school education is conducted on the supposition that the medium is the message. But sometimes the medium is just the medium. What matters is the way people think about themselves while engaged in the two activities. A person who becomes a citizen of the literary world enters a hierarchical universe. There are classic works of literature at the top and beach reading at the bottom. A person enters this world as a novice, and slowly studies the works of great writers and scholars. Respect is paid to the writers who transmit that wisdom. A citizen of the Internet has a very different experience. The Internet smashes hierarchy and is not marked by respect. Maybe it would be different if it had been invented in Victorian England, but Internet culture is set in contemporary America. Internet culture is egalitarian. The young are more accomplished than the old. The new media is supposedly cleverer than the old media. The dominant activity is free-wheeling, disrespectful, antiauthority disputation. These different cultures foster different types of learning. The great essayist Joseph Epstein once distinguished between being well informed, being hip and being cultivated. The Internet helps you become well informed—knowledgeable about current events, the latest controversies and important trends. The Internet also helps you become hip—to learn about what"s going on, as Epstein writes, "in those lively waters outside the boring mainstream." But the literary world is still better at helping you become cultivated, mastering significant things of lasting importance. To learn these sorts of things, you have to defer to greater minds than your Own. You have to take the time to immerse yourself in a great writer"s world. You have to respect the authority of the teacher. Right now, the literary world is better at encouraging this kind of identity. The Internet culture may produce better conversationalists, but the literary culture still produces better students. It"s better at distinguishing the important from the unimportant, and making the important more prestigious. Perhaps that will change. Already, more "old-fashioned" outposts are opening up across the Web. It could be that the real debate will not be books versus the Internet but how to build an Internet counterculture that will better attract people to serious learning.

单选题In a supermarket, all commodities are open to customers who can select what they need ______.

单选题Many people like the color white as it is a ______ of purity.

单选题Such changes, A combined with the erosion of B the area's barrier islands, and the Bush administration's policy of C opening up more wetlands to development, weakened the natural frontline defense against a hurricane storm surge D and leave the city more vulnerable to death and destruction.

单选题The Chinese Red Cross______ a generous sum to the relief fund for the physically disabled.

单选题Thelastparagraphshowsthattheauthor‘sattitudetowardsthereliabilityofnewtechniquesis