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

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

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.

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 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Today our knowledge of food and what it does for our bodies are far more advanced than that of the old times. Now we know about vitamins and how each kind of vitamin helps in the growth of a particular part of our body. There are on the market all kinds of vitamins which one can take to make up for one"s lack of certain important things, which are needed for good health. Of course, if we eat well and properly, the food that we eat will take care of our body and so there is no need to take any kinds of vitamins unless our doctor tells us that our bodies are short of something, which can be supplied by them. Generally speaking, everything we eat does some good to our body. But if we eat too much of one kind of food and pay too little attention to others, we may have too much of one kind and not enough of others. Then we may be in trouble. We are often told that we must eat some meat at each meal in order to get the necessary proteins. That is only partly true, for proteins are not found only in meat. We can also get them from some vegetables. The best advice about what to eat is that we should eat all kinds of food but never too much of any.

单选题People are more likely to accept the decision if they are ______ in making it.

单选题Successful innovations have driven many older technologies to extinction and have resulted in higher productivity, greater consumption of energy, increased demand for raw materials, accelerated flow of materials through the economy and increased quantities of metals and other substances in use per person. The history of industrial development is full of examples. In 1870, horses and mules were the prime source of power on U. S. farms. One horse or mule was required to support four human beings—a ratio that remained almost constant for many decades. At that time, had a national commission been asked to forecast the horse and mule population for 1970, its answer probably would have depended on whether its consultants were of an economic turn of mind. Had they been "economists", they would have recognized that the power of steam had already been harnessed to industry and to land and ocean transport. They would have recognized further that would be only a matter of time before steam would be the prime source of power on the farm. It would have been difficult for them to avoid the conclusion that the horse and mule population would decline rapidly.

单选题We want to preserve the character of the town while improving the facilities.

单选题 Passage 4 There is nothing illogical or synthetic about the humility of great bookmen in calling attention to the limitations of the book. No book can {{U}}(1) {{/U}} us to know everything that is to be known, or feel everything that is to be felt. A book is part of life, not a substitute {{U}}(2) {{/U}} it. It is not a fit {{U}}(3) {{/U}} for worship or enshrinement. It loses its charm and much of its value when accepted uncritically. No one would have been more {{U}}(4) {{/U}} than Aristotle if he could have known of the excessive and {{U}}(5) {{/U}} veneration that would be given to his ideas in centuries to {{U}}(6) {{/U}} When his works became the last words of advance knowledge, such knowledge became neither advanced nor vital. The particular occasion for these remarks is that there are {{U}}(7) {{/U}} here and there that some of us in the book world may be {{U}}(8) {{/U}} ourselves too seriously. In the effort to increase book reading some extravagant things are being said about books. It is made to{{U}} (9) {{/U}} that nothing is happening now that has not happened before, and that the only true approach to understanding is {{U}}(10) {{/U}} books. We do neither service nor justice to books by {{U}}(11) {{/U}} upon them such omnipotence and omniscience. Many of the answers we need today are not necessarily to be found between {{U}}(12) {{/U}} . There are elements of newness in the present {{U}}(13) {{/U}} of man that will not readily be {{U}}(14) {{/U}} of by required reading or ready reference. Books are not slide rules or blueprints for {{U}}(15) {{/U}} automatic answers. What is needed is a mighty blend of the wisdom of the ages with fresh, razor-edged analytical thought.