题目内容
（请给出正确答案）
at the observation window, I can enjoy a birdeye view of the city.
[A] Seating
[B] Seated
[C] To sit
[D] Sitting down
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更多“at the observation window, I c…”相关的问题
A．former plan
B．original observation
C．original estimate
D．former observation
A. regard
B. account
C. counting
D. observation
There are three types of interviews depending on the degree of freedom on the part of the interviewer.They are （）.
A.informal interview, formal interview and telephone interview
B.open interview, semi-structured interview and structured interview
C.unstructured interview, structured interview and spontaneous interview
D.conversation, observation and fieldwork
Among the devastating consequences of AIDS has 【21】______ its epidemic spread in the developing world. The disease has caused 【22】______ suffering, debilitation, loss of life and disruption of family, social and economic 【23】______ Because of the considerable expense and logistical difficulty in providing antiviral drugs to populations 【24】______ with the Human Immunodeficiency Virus 【25】______ the world, the biomedical community is looking towards vaccines to help solve this compelling problem.
The search for an AIDS vaccine began more than 15 years ago with great 【26】______ and high expectations. With the 【27】______ of the Human Immunodeficiency Virus (HIV) as the cause of AIDS, it seemed that a 【28】______ would follow closely behind. But despite a large concerted effort, the problem has proven more difficult than 【29】______ , and progress has not 【30】______ the 【31】______ hopes. Here I review the 【32】______ scientific obstacles confronting the development of an effective HIV vaccine, and I consider 【33】______ strategies to overcome these obstacles.
It is instructive to consider the circumstances that have 【34】______ to past successes in vaccine development. The smallpox vaccine is 【35】______ the most successful inventions in the history of 【36】______ Why, 200 years ago, without the benefit of modern biotechnology, did the smallpox vaccine succeed so readily while an AIDS vaccine 【37】______ elusive？ The answer lies in an experiment of nature that provided, to an astute observer, a clear direction for smallpox vaccine development. In this classic story of 【38】______ discovery, Edward Jennet noticed that milk maids who had previously contracted cowpox were 【39】______ to smallpox infection. This observation was the critical event leading to the finding that the cowpox virus cross-reacted immunologically with the smallpox virus and could 【40】______ be used to protect against smallpox.
【21】
A．on
B．with
C．been
D．about
For some time past it has been widely accepted that babies-and other creatures-learn to do things because certain acts lead to “rewards”; and there is no reason to doubt that this is true. But it used also to be widely believed that effective rewards, at least in the early stages, had to be directly related to such basic physiological (生理的)“drives” as thirst or hunger. In other words, a baby would learn if he got food or drink or some sort of physical comfort, not otherwise.
It is now clear that this is not so. Babies will learn to behave in ways that produce results in the world with no reward except the successful outcome.
Papousek began his studies by using milk in the normal way to“reward” the babies and so taught them to carry out some simple movements, such as turning the head to one side or the other. Then he noticed that a baby who had had enough to drink would refuse the milk but would still go on making the learned response with clear signs of pleasure. So he began to study the children's responses in situations where no milk was provided. He quickly found that children as young as four months would learn to turn their heads to right or left if the movement“switched on” a display of lights-and indeed that they were capable of learning quite complex turns to bring about this result, for instance, two left or two right, or even to make as many as three turns to one side.
Papousek's light display was placed directly in front of the babies and he made the interesting observation that sometimes they would not turn back to watch the lights closely although they would“smile and bubble” when the display came on. Papousek concluded that it was not primarily the sight of the lights which pleased them, it was the success they were achieving in solving the problem, in mastering the skill, and that there exists a fundamental human urge to make sense of the world and bring it under intentional control.
According to the author, babies learn to do things which______.
A．are directly related to pleasure
B．will meet their physical needs
C．will bring them a feeling of success
D．will satisfy their curiosity
The Moon, which has undergone a distinct and complex geological history, presents a
striking appearance. The moon may be divided into two major terrains: the maria (dark
lowlands) and the terrace(bright highlands). The contrast in the reflectivity (the capability
of reflecting light) of these two terrains suggested to many early observers that the two
(5) terrains might have different compositions, and this supposition was confirmed by missions to
the Moon such as Surveyor and Apollo. One of the most obvious differences
between the terrains is the smoothness of the maria in contrast to the roughness of the
highlands. This roughness is mostly caused by the abundance of craters; the highlands are
completely covered by large craters(greater than 40-50 km in diameter), while the craters
(10) of the maria tend to be much smaller. It is now known that the vast majority of the Moon's
craters were formed by the impact of solid bodies with the lunar surface.
Most of the near side of the Moon was thoroughly mapped and studied from telescopic
pictures years before the age of space exploration. Earth-based telescopes can resolve
objects as small as a few hundred meters on the lunar surface. Close observation of
(15) craters, combined with the way the Moon diffusely reflects sunlight, led to the
understanding that the Moon is covered by a surface layer, or regolith, that overlies the
solid rock of the Moon. Telescopic images permitted the cataloging of a bewildering array
of land forms. Craters were studied for clues to their origin; the large circular maria were
(20) seen. Strange, sinuous features were observed in the maria. Although various land forms
were catalogued, the majority of astronomers' attention was fixed on craters and their
origins.
Astronomers have known for a fairly long time that the shape of craters changes as
they increase in size. Small craters with diameters of less than 10-15 km have relatively
(25) simple shapes. They have rim crests that are elevated above the surrounding terrain,
smooth, bowl-shaped interiors, and depths that are about one-fifth to one-sixth their diameters.
The complexity of shape increases for larger craters.
What does the passage mainly discuss？
A．What astronomers learned from the Surveyor and Apollo space missions
B．Characteristics of the major terrains of the Moon
C．The origin of the Moon's craters
D．Techniques used to catalogue the Moon's land forms
When families gather for Christmas dinner, some will stick to formal traditions dating back to Grandma's generation. Their tables will be set with the good dishes and silver, and the dress code will be Sunday-best.
But in many other homes, this china-and-silver elegance has given way to a stoneware-and-stainless in formality, with dresses assumig an equally casual-Friday look. For hosts and guests, the change means greater simplicity and comfort. For makers of fine china in Britain, it spells economic hard times.
Last week Royal Doulton, the largest employer in Stoke-on-Trent, announced that it is 'eliminating 1,000 jobs--one-fifth of its total workforce. That brings to more than 4,000 the number of positions lost in 18 months in the pottery region. Wedgwood and other pottery factories made cuts earlier.
Although a strong pound and weak markets in Asia play a role in the downsizing, the layoffs in Stoke have their roots in earthshaking social shifts. A spokesman for Royal Doulton admitted that the company "has been somewhat slow in catching up with the trend" toward casual dining. Families eat together less often, he explained, and more people eat alone, either because they are single or they eat in front of television.
Even dinner parties, if they happen at all, have gone casual. In a time of long work hours and demanding family schedules, busy hosts insist, rightly, that it' s better to share a takeout pizza on paper plates in the family room than to wait for the perfect moment or a "real" dinner party. Too often, the perfect moment new ex comes. Iron a fine-patterned tablecloth？ Forget it. Polish the silver？ Who has time？
Yet the loss of formality has its down side. The fine points of etiquette that children might once have learned at the table by observation or instruction from parents and grandparents (" Chew with your mouth dosed." "Keep your elbows off the table.") must be picked up elsewhere. Some companies now offer etiquette seminars for employees who may be competent professionally but clueless socially.
The trend toward casual dining has resulted in （）．
A.bankruptcy of fine china manufacturers
B.shrinking of the pottery industry
C.restructuring of large enterprises
D.economic recession in Great Britain
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int w= ' A ' ,x=14,y=15;
w=((x||y)&&(w＜ ' a ' ));
A)-1
B)NULL
C)1
D)0
