单选题What is the characteristic of the Martian surface according to observations over the past 20 years?

单选题Every year television stations receive hundreds of complaints about the loudness of advertisements. However, federal rules forbid the practice of making ads louder than the programming. In addition, television stations always operate at the highest sound level allowed for reasons of efficiency. According to one NBC executive, no difference exists in the peak sound level of ads and programming. Given this information why do commercials sound so loud? The sensation of sound involves a variety of factors in addition to its speak level. Advertisers are skilful at creating the impression of loudness through their expert use of such factors. One major contributor to the perceived loudness of commercials is that much less variation in sound level occurs during a commercial. In regular programming the intensity of sound varies over a large range. However, sound levels in commercials tend to stay at or near peak levels. Other "tricks of the trade" are also used. Because low-frequency sounds can mask higher frequency sounds, advertisers filter out any noises that may drown out the primary message. In addition, the human voice has more auditory (听觉的) impact in the middle frequency ranges. Advertisers electronically vary voice sounds so that they stay within such a frequency band. Another approach is to write the script so that lots of consonants are used, because people are more aware of consonants than vowel sounds. Finally, advertisers try to begin commercials with sounds that are highly different from those of the programming within which the commercial is buried. Because people become adapted to the type of sounds coming from programming, a dramatic change in sound quality draws viewer"s attention. For example, notice how many commercials begin with a cheerful song of some type. The attention-getting property of commercials can be seen by observing one- to two-year-old children who happen to be playing around a television set. They may totally ignore the programming. However, when a commercial comes on, their attention is immediately drawn to it because of its dramatic sound quality.

单选题In the Arctic Circle, it is not that Eskimos lack ability or industry, but the surroundings restrict constructive effort to the barest necessities of existence. This effectually retards progress to higher development. Agriculture is impossible all along the thousands of miles of the north shore. The only wood is such as drifts in. Other than this driftwood, the only available building materials are snow, ice, stone, and bones of animals. All of these have been used for habitations and storage places, differing in various tribes according to the requirements and skill of the workers. The lack of necessary timbers to build walls and span wide spaces is probably one reason why these tribes construct their houses at least partly beneath the surface of the ground. This device also makes the houses more impervious (不能渗透的) to the cold. Most of us are inclined to think that the Eskimo lives always in an igloo or snow house. This is not entirely true. After the long cold winter, the family is very likely to move, when the weather permits, into a tent of sealskin. The actual construction of such a tent is similar to that used by other, more southerly tribes and will be described later. The snow house, however, is an interesting and unique habitation. Our summer campers will not build with snow, but the delicate art is worth recording and some of our winter camps in the mountains might try to make snow houses.

单选题Large lecture classes are frequently regarded as a necessary evil. Such classes (21) be offered in many colleges and universities to meet high student (22) with limited faculty resource, (23) teaching a large lecture class can be a (24) task. Lecture halls are (25) large, barren, and forbidding. It is difficult to get to know students. Students may seem bored in the (26) environment and may (27) read newspapers or even leave class in the middle of a lecture. Written work by the students seems out of the (28) . Although the challenges of teaching a large lecture class are (29) , they are not insurmountable. The solution is to develop (30) methods of classroom instruction that can reduce, if not (31) , many of the difficulties (32) in the mass class. In fact, we have (33) at Kent State University teaching techniques which help make a large lecture class more like a small (34) . An (35) but important benefit of teaching the course (36) this manner has involved the activities of the teaching assistants who help us mark students' written work. The faculty instructor originally decided to ask the teaching assistants for help (37) this was the only practical way to (38) that all the papers could be evaluated. Now those (39) report enjoying their new status as "junior professors", gaining a very different (40) on college education by being on the other side of the desk, learning a great deal about the subject matter, and improving their own writing as a direct result of grading other students' papers.

单选题Client: Excuse me. I tried to withdraw some money at the ATM outside, but the transaction failed. Bank Clerk: Maybe it's just the wrong denomination. The smallest at the ATM is ten dollars. Client: ______ A. What a nuisance. B. So the thing is like this. C. So it's too small. D. I see.

单选题Ann: Could you go to the store nearby fight away? I need a few things for painting. Betty: ______. A. Yes, storing a few things away is quite necessary, right? B. For me, going there is not a problem. I'd like to do some exercises. C. Yes. I could. I want painting. D. All right. What do you want me to get?

单选题Not so long ago almost any student who successfully completed a university degree could, find a good career quite easily. Companies toured the academic institutions, competing with each other to select graduates. However, those days are gone, even in Hong Kong, and nowadays graduates often face strong competition in the search for jobs. Most careers organizations highlight three stages for graduates to follow in the process of securing a suit- able career: recognizing abilities, matching these to available jobs and presenting them well to possible employers, Job seekers have to make a careful assessment of their own abilities. One area of assessment should be of their academic qualifications, which would include special skills within their subject area. Graduates should also consider their own personal values and attitudes. An honest assessment of personal interests and abilities such as creative skills, or skills acquired from work experience, should also be given careful thought. The second stage is to study the opportunities available for employment and to think about how the general employment situation is likely to develop in the future. To do this, graduates can study job and position information in newspapers, or they can visit a careers office, write to possible employers for information or contact friends or relatives who may already be involved in a particular profession. After studying all the various options, they should be in a position to make informed comparisons between various careers. Good personal presentation is essential in the search for a good career, job application forms and letters should, of course, be filled in carefully and correctly, without grammar or spelling errors. Where additional information is asked for, job seekers should describe their abilities and work experience in more depth, with examples if possible. They should try to balance their own abilities with the employer% needs, explain why they are interested in a career with the particular company and try to show that they-already know something about the company and its activities. When graduates go to an interview, they should prepare properly by finding out all they can about the possible employer. Dressing suitably and arriving for the interview on time are also important. Interviewees should try to give positive and helpful answers and should not be afraid to ask questions about anything they are unsure about. This is much better than pretending to understand a question and giving an unsuitable answer.

单选题Customer: Can I try this dress on, please? Saleswoman :______ A. Of course, try it on in the fitting room, please. B. This dress is on sale for half its regular price. C. Try it on, then. You don't need to ask. D. Sure, the fitting rooms are next to the stairs.

单选题Speaker A: Well, I'm really glad I talked to Doug about the problem I was having with my girlfriend. He gave me some excellent advice.Speaker B: Great. That's what I like about Doug.______, and he's always prepared to stop what he's doing and help you out when you need it.

单选题Today children ______ everywhere in China. A. take good care of B. have taken good care of C. had been taken good care of D. are being taken good care of

单选题I felt like ______ to him, "Don't be such a complainer all the time." A. say B. to say C. saying D. said

单选题Predictions of large populations of robots in industry have yet to come true. For a decade or more, manufacturers of big robots have explained how their machines can make industry more competitive and productive. The market for (1) robots is now oversupplied, and the driving force of the robotics (机器人技术) revolution is (2) to be with makers of machines that handle a few kilos at most. "Heavy-robot manufacturers are in some difficulty (3) finding customers. They are offering big (4) just to get in the door. There has been a (5) growth everywhere in the numbers of robots, so we have to admit we are either deceiving (6) or that the market is slowly growing," said John Reekie, Chairman of Colne Robotics. "The following things must happen (7) the robotics revolution to occur. We must achieve widespread robot literacy(文化), (8) there has been a computer literacy program, there must be a robot literacy campaign. We must also (9) not just a cut in, but a collapse of robot prices. (10) , some kind of artificial intelligence needs to be available./

单选题Bring the umbrella on the picnic even though you don't anticipate ______ it.

单选题Some sufferers will quickly be restored to perfect health, ______ others will take a longer time. A. which B. where C. when D. whereas

单选题In contrast to the new teachers, the middle-standing and veteran teachers seem to have made a remarkable improvement in their ability to ______.

单选题Most people can't ______ the day without at least one cup of tea or coffee. A. get through B. get on C. get at D. get by

单选题Migration is usually defined as "permanent or semi-permanent change of residence". However, our concern is with movement between nations, not with internal migration within nations, although such movements often exceed international movements in volume. Today, the motives of people who move short distances are very similar to those of international migrants. Students of human migration speak of "push" and "pull" factors, which influence an individual's decision to move from one place to another. Push factors are associated with the place of origin. A push factor can be as simple and mild a matter as difficulty in finding a suitable job, or as traumatic as war, or severe famine. Obviously, refugees who leave their homes with guns pointed at their heads are motivated almost entirely by push factors (although pull factors do influence their choice of destination). Pull factors are those associated with the place of destination. Most often these are economic, such as better job opportunities or the availability of good land to farm. In general, pull factors add up to an apparently better chance for a good life and material well-being than is offered by the place of origin. When there is a choice between several attractive potential destinations, the deciding factor might be a non-economic consideration such as the presence of relatives, friends, or at least fellow countrymen already established in the new place who are willing to help the newcomers settle in. Besides push and pull factors, there are what the sociologists call "intervening obstacles." Even if push and (or) pull factors are very strong they still may be outweighed by intervening obstacles, such as the distance of the move, the trouble and cost of moving, the difficulty of entering the new country, and the problems likely to be encountered on arrival. The decision to move is also influenced by "personal factors" of the potential migrant. The prospect of packing up everything and moving to a new and perhaps very strange environment may appear interesting and challenging to an unmarried young man and appallingly difficult to a slightly older man with a wife and small kids. Similarly, the need to learn a new language and customs may excite one person and frighten another. Regardless of why people move, migration of large numbers of people causes conflict. The United States and other western countries have experienced adjustment problems with each new wave of immigrants. It has usually taken several decades for each group to be accepted into the mainstream of society in the host country.

单选题(Less women) than men (are attracted) to careers in the physical sciences, even though (there are now) more women in the sciences (than ever before).

单选题{{B}}练习九{{/B}} A new era is upon us. Call it what you will: the service economy, the information age, the knowledge society. It is all translated to a fundamental change in the way we work. Already we've partly been there. The percentage of people who earn their living by making things has fallen dramatically in the Western World. Today the majority of jobs in America, Europe and Japan (two thirds or more in many or these countries) are in the service industry, and the number is on the rise. More women are in the work force than ever before. There are more part-time jobs. More people are self-employed. But the breadth of the economic transformation can't be measured by numbers alone, because it is also giving rise to a radical new way of thinking about the nature of work itself. Long-held notions about jobs and careers, the skills needed to succeed, even the relation between individuals and employers—all these are being changed. We have only to look behind us to get some sense of what may lie ahead. No one looking ahead 20 years possibly could have foreseen the ways in which a single invention, the chip (集成电路), would transform our world thanks to its applications in personal computers, digital communications and factory robots. Tomorrow's achievements in biotechnology, artificial intelligence or even some still unimagined technology could produce a similar wave of dramatic changes. But one thing is certain: information and knowledge will become even more vital, and the people who possess it, whether .they work in manufacturing or services, will have the advantage and produce the wealth. Computer knowledge will become as basic a requirement as the ability to read and write The ability to solve problems by applying information instead of performing routine tasks will be above all else. If you cast your mind ahead 10 years, information services will be predominant It will be the way you do your job.

单选题The shilpping company will give you a ______ of freight if the goods are lost.