单选题Food is to the blood ______ reading is to the mind.

单选题The United Nations Conferences on the Law of the sea would soon produce an ocean-mining treaty following its ______ declaration in 1970 that oceans were the heritage of mankind.

单选题The image of an unfortunate resident having to climb 20 flights of stairs because the lift is ______ is now a common one. A. out of the way B. on order C. out of order D. in no way

单选题The electrical impulses are finally ______ back into the spots of light that make up the picture on the television screen.(2010年北京航空航天大学考博试题)

单选题Differences in positions adopted by oxygen and hydrogen atoms account for variations in the crystalline structure of different forms of ice.

单选题The increasing popularity of the motorcycle as a convenience, economical form of transportation has been just short of astounding.

单选题The prevailing union of passionate interest in detailed facts with equal devotion to abstract generalization is a hallmark of our present society; in the past this union appeared, at best, ______and as if by chance.

单选题It was all agreed that the first problem the new government would have to ______was unemployment.(2003年南京大学考博试题)

单选题He tried but failed in his attempt to avoid being prosecuted by practicing bribery.

单选题Chlorine is a mainstay in most swimming pools in the United States, and is used to eradicate bacteria. A bacteria-free pool will usually ensure that swimmers won't contract a serious illness if they spend time in, and possibly ingest the water. When chlorine is added to pool water, a chemical reaction occurs whereby the chlorine breaks down into a legion of chemicals that combine to kill bacteria that may be in water. These chemicals, specifically hypochlorous acid and hypochlorite ion, eliminate bacteria by annihilating and then oxidizing the abhorrent cells. When this chemical reaction occurs, the bacteria are rendered essentially harmless. This chemical reaction doesn't occur immediately — individual components within chlorine take varying amounts of time to interact with the bacteria, creating an almost time-release-type of kill in the pool water. Chlorine must be regularly replenished. As they react, the hypochlorous acid and hypochlorite ion combine to create a particular acceptable pH level in the pool water. A pH is a measure of the alkalinity and acidity present; a pH value of 7 represents a neutral value, and 7. 4 is the pH value of the human tear. The pH ratio must be regularly monitored to ensure a consistent optimum ram — one usually kept within the spectrum of 7 to 8 as measured by a reliable pH measuring kit. As the chemicals in chlorine complete their reactions, they break down and are no longer effective in keeping the pool water neutralized. Additional chlorine must be added to water at specific times. Outdoor pools that are in direct sunlight need to have water added more often because the chemical reaction time for chlorine is increased and its effectiveness water added more often because the chemical reaction time for chlorine is increased and its effectiveness is reduced in these conditions. Since the hypochlorite ion is an especially potent chemical capable of fading fabrics and paint, most people are meticulous about rinsing chlorine from potentially affected areas. Although chlorine is inexpensive and widely available, some people find the bleach smell to be repugnant and the, distinct aroma present at many swimming pools to be overwhelming. These people may not be able to enjoy aquatic pursuits in those pools that employ chlorine as a cleansing agent. Other people may find that inhaling chlorine at the high levels present around some pools may be difficult to tolerate. Still others may experience skin irritation after swimming in a pool containing chlorine. Although there are other chemicals and compounds available to clean swimming pools, they may be prohibitively expensive or incapable of killing all types of bacteria present in the water.

单选题In the 1970 rebel, the speech made by Mishima ______.

单选题(No wonder) that (man's) great dream has been someday to control the weather. The first step toward control is, of course, knowledge, and scientists have been (hard at work) for years trying to (keep track with) the weather.

单选题Part of the teacher of reading' s involvement in the development of a literate society is through ______.

单选题As a business model, the world of publishing has always been a somewhat sleepy enclave, but now all that seems poised to change. Several companies have moved aggressively into a new business endeavor whose genesis comes from the question: Who owns the great works of literature? Text-on-demand is not a completely new idea, of course. In the 1990s,the Gutenberg project sought volunteers to type literary classics that had expired copyrights into word processing files so that scholars would have searchable databases for their research. Most of the works of Shakespeare, Cervantes, Proust, and Moliere were to be found free online by as early as 1995. However, now large-scale companies have moved into the market, with scanners and business plans, and are looking for bargain basement content. These companies are striking deals with libraries, and some publishers, to be able to provide their content, for a price, to individual buyers over the Internet. At stake are the rights to an estimated store of 30 million books, most of which are now out of print. Many of these books are now also in the public domain, giving any company the right to sell them online. Still, a good portion of the books a general audience want to buy is still under copyright. The urgent question: Who owns those copyrights? In the case of all too many books put out more than 20 years ago by now-defunct publishing companies, the answer is unclear—a situation the new text-on-demand companies are eager to exploit. An association of publishers has sued, claiming massive copyright infringement. The case is several years away from trial.

单选题For me, scientific knowledge is divided into mathematical sciences, natural sciences or sciences dealing with the natural world(physical and biological sciences), and sciences dealing with mankind(psychology, sociology, all the sciences of cultural achievements, every kind of historical knowledge). Apart from these sciences is philosophy about which we will talk shortly. In the first place, all this is pure or theoretical knowledge, sought only for the purpose of understanding, in order to fulfill the need to understand what is essential and substantial to man. What distinguishes man from animal is that he knows and needs to know. If man did not know that the world existed and the world was of a certain kind that he was in the world and that he himself was of a certain kind, he wouldn't be man. The technical aspects of applications of knowledge are equally necessary for man and are of the greatest importance, because they also contribute to defining him as man and permit him to pursue a life increasingly more truly human. But even while enjoying the results of technical progress, he must defend the primacy and independence of pure knowledge. Knowledge sought directly for its practical applications will have immediate and foreseeable success, but not the kind of important result whose revolutionary scope is in large part unforeseen, except by the imagination of the Utopians. Let me recall a well-known example. If the Greek mathematicians had not applied themselves to the investigation of conic sections, zealously and without the least suspicion that it someday be useful, it would not have been possible centuries later to navigate far from shore. The first men to study the nature of electricity could not imagine that their experiments, carried on because of mere intellectual curiosity, would eventually lead to modern electrical technology, without which we can scarcely conceive of contemporary life. Pure knowledge is valuable for its own sake, because the human spirit cannot resign itself to ignorance. But, in addition, it is the foundation for practical results that would not have been reached if this knowledge had not been sought disinterestedly.

单选题Which of the following statement about the modern society is TRUE according to the passage?

单选题Heather scrupulously avoided any topic likely to ______ suspicion as to his motives.

单选题He is such a______that he built a porch for his house last summer during his vacation.