单选题I tried to relax because I knew I would use up my oxygen sooner ______. A. the more excited I got B. and more I got excited C. I got more excited D. and I got more excited

单选题If you can't turn the key, try ______ some oil in the lock. A. put B. putting C. to put D. to putting

单选题A: I' m taking my driving test tomorrow. B: ______

单选题{{B}}Questions 21-25 are based on the following passage:{{/B}} The growth of population during the past few centuries is no proof that population will continue to grow straight upward toward infinity and doom. On the contrary, demographic history offers evidence that population growth has not been at all constant. According to paleo-ecologist Edward Deevey, the past million years show three momentous changes. The first, a rapid increase in population around one million B. C. , followed the innovations of tool-making and tool-using. But when the new power from the use of tools had been exploited, the rate of world population growth fell and became almost stable. The next rapid jump in population started perhaps 10,000 years ago, when men began to keep herds, plow and plant the earth. Once again when initial productivity gains had been absorbed, the rate of population growth abated. These two episodes suggest that the third great change, the present rapid growth, which began in the West between 250 and 350 years ago, may also slow down when, or if technology begins to yield fewer innovations. Of course, the current knowledge revolution may continue without foreseeable end. Either way contrary to popular belief in constant geometric growth-- population can be expected in the long run to adjust to productivity.

单选题After the guests left, she spent half an hour ______ the sitting-room.

单选题She ought to stop work: she has a headache because she______ too long.

单选题Speaker A: Want to come over Thursday for supper? Speaker B: ______.

单选题If tulip bulbs(郁金香鳞茎) are planted (in the fall), they (could have been) expected (to bloom) the (following) spring.A. in the fallB. could have beenC. to bloomD. following

单选题 Change, or the ability to {{U}}(31) {{/U}} oneself to a changing environment is essential {{U}}(32) {{/U}} evolution. The farmer whose land is required for housing or industry must adapt himself: he can transfer to another place and master the problems {{U}}(33) {{/U}} to it; he can change his occupation, perhaps {{U}}(34) {{/U}} a period of training; or he can starve to death. A nation which can't adapt its trade or defense requirements to {{U}}(35) {{/U}} world conditions faces an economic and military disaster. Nothing is fixed and permanently stable. {{U}}(36) {{/U}} must be movement forward, which is progress of a sort, and movement backward, which is decay and deterioration. In a changing world, tradition can be a force for good or for evil. {{U}}(37) {{/U}} long as it offers a guide, it helps the ignorant and the uninformed to take a step {{U}}(38) {{/U}} and, thereby adapt themselves to {{U}}(39) {{/U}} circumstances. But if we make an idol of tradition, it ceases to be a guide. It becomes an obstacle {{U}}(40) {{/U}} on the path of course. Man is to accept the help which tradition can give but to be well aware of its limitations in a changing world.

单选题Before TV, the common man (seldom never) (had) the opportunity to see and (hear) his leaders express (their) views.

单选题The world's greatest sporting event, the Olympic games, upholds the amateur ideal that ______ matters is not winning but participating. A. anything B. it C. what D. everything

单选题Industrial safety does not just happen. Companies (31) low accident rates plan their safety programs, work hard to organize them, and continue working to keep them (32) and active. When the work is well done, a (33) of accident-free operations is established (34) time lost due to injuries is kept at a minimum. Successful safety programs may (35) greatly in the emphasis placed on certain aspects of the program. Some place great emphasis on mechanical guarding. Others stress safe work practices by (36) roles or regulations. (37) others depend on an emotional appeal to the worker. But, there are certain basic ideas that must be used in every program if maximum results are to be obtained. There can be no question about the value of a safety program. From a financial stand-point alone, safety (38) . The fewer the injury (39) , the better the workman's insurance rate. This may mean the difference between operating at (40) or at a loss.

单选题We must ______ that the experiment is gong to be controlled as rigidly as possible. A. assure B. secure C. ensure D. endure

单选题 Regular child care provided outside home or by someone other than the mother does not in itself undermine healthy emotional connections between mothers and their 15-month-old infants, according to a long-term national study. The finding holds even if care begins during the first 3 months after birth and runs for 30 hours or more per week. Among infants who receive unkind and unresponsive care from their mothers, however, the mother-child relationship may be damaged. "This research helps us put apart complexities regarding child care that have not previously been studied in detail," contends Jay Belsky, a psychologist. The investigation consists of 1,153 children and their families living in or near Boston. The youngsters, no more than 1 month old when they entered the study in 1991, will be tracked until the age of 7. Experimenters administered questionnaires to mothers in their homes and videotaped baby caretakers interacting with the kids at ages l, 6, and 15 months. Independent observers rated the quality of each child care efforts and noted infant nervousness. Unlike most previous studies, this one allows researchers to observe each caretaker's personality at child nursing, and kids' emotional reaction by the equipment.

单选题 The economy in the United States is heavily dependent on aluminum, a material widely used in the construction of buildings and in making such diverse things as cars, airplanes, and food containers, in 1979 Americans used over five million tons of new aluminum, and one and a half million tons of recycled aluminum. Some ninety percent of the bauxite (矾土) ore from which new aluminum is normally derived had to be imported to meet the demand. Poorer ores are abundant in the United States, however, and researchers at Purdue University may recently have found a way to obtain aluminum magnetically from these. Although aluminum is not attracted by ordinary magnets, under special conditions it becomes temporarily "paramagnetic", or very weakly responsive to a magnetic field. This is achieved by immersing ore particles in water to which certain salts have been added and then filtering the ore through steel wool in the presence of a strong magnetic field. It is hoped that this technique will reduce the amount of high-grade aluminum the United States must import.

单选题A rogue loose called a hacker could take control of the entire system by implanting his own instructions in the software and then he could program the computer to erase any sign ______. A. of his being ever there B. he ever has been there C. of his having ever been there D. of him having ever been there

单选题The comprehension passages on this course are designed to help you increase your speed. A higher reading rate, with no loss of comprehension, will help you in other subjects as well as English, and the general principles apply to any language. Naturally, you will read every book at the same speed. You would expect to read a newspaper, fox example, much more rapidly than a physics or economics textbook but you can raise your average reading speed over the whole range of materials you wish to cover so that the percentage gain will be the same whatever kind of reading you are concerned with. The reading passages which follow are all of an average level of difficulty for your stage of instruction. If you get to the point where you can read books of average difficulty at between 40 and 50 w.p.m. with 70% or more comprehension, you will be doing quite well, though of course any further improvement of speed with comprehension will be a good thing. When you practise reading with passages shorter than book length, do not try to take in each word separately, one after the other. It is much more difficult to grasp the broad theme of the passage this way, and you will also get stuck on individual words which may not be absolutely essential to a general understanding of the passage. It is a good idea to skim through the passage very quickly first (say 500 words in a minute or so) to get the general idea of each paragraph. Titles, paragraph headings and emphasized words (underlined or in italics) can be a great help in getting this skeleton outline of the passage.

单选题Interviewer: So what do you do, Tony?Tony: I'm a hairdresser.Interviewer: Oh. ______?Tony: Well, I love my customers. Some of them are so friendly. But it's tiring work. I work long hours and I'm on my feet all day.

单选题A: How's the young man? B. ______ A. He's twenty. B. He's much better. C. He's a doctor. D. He's David.

单选题A: I'm exhausted. I had to work until 2 o'clock this morning. B: ______ A. Don't worry too much. You can do it later. B. Take it easy. You didn't have to work so hard. C. Take time off and let it be. D. Take it or leave it. You don't have to do it.