单选题He stepped {{U}}gingerly{{/U}} into the ramshackle old house.
单选题Colleges in the (newly formed) United Sates, (in recovering), from the adverse effects of the American Revolution, inaugurated (a broad curriculum) (in response of) social demands.
单选题
单选题Nail polish is made from cellulose Ulacquer/U, and opaque nail polish can be made by adding titanium oxide.
单选题The concept of a loyal opposition—the ______ of modern
democracy—rarely prevails and, much more frequently, opposition is equated with
treason and ruthlessly suppressed.
A. loop
B. essence
C. equivalent
D. velocity
单选题English speakers pick up pitch in the right hemispheres of their brains, but speakers of certain other languages perceive it on the left as well. It all depends on what you want to learn from pitch, Donald Wong of the Indiana School of Medicine in Indianapolis told the meeting last week.
Earlier studies have shown that when an English speaker hears pitch changes, the right prefrontal cortex leaps into action. This fits in with the idea that emotive nuances of language—which in English are often carried by the rise and fall of the voice—are perceived on the fight.
But in "tonal" languages like Thai, Mandarin and Swedish, pitch not only carries emotional information, but can also alter the meaning of a word. Wong and his colleagues suspected that a speaker of tonal language would register pitch in .the left side of the brain—in particular Broca"s area, which processes the linguistic content of language.
To test this, the team asked English speakers and Thai speakers to listen to 80 pairs of Thai words, and tracked the blood flow in their brains using positron emission tomography. The volunteers had to decide whether the two words sounded the same, either by consonant or by tone. In some eases, the words had no intelligible meaning.
None of the words was emotionally charged, so even when Thai speakers could understand them, there was no fight-side activation. But sure enough the Thai speakers consistently lit up the left side of the brain, especially Broca"s area, while the English speakers did not.
The researchers are now planning to repeat the experiment with Thai speakers using whole sentences, complete with emotional information. "Both hemispheres will be engaged." predicts Wong.
单选题The population in last area was growing rapidly. Needless to say, the housing problem there {{U}}cried out{{/U}} for immediate solution.
单选题After a few short but
interminable
seconds, U. S. Astronaut Neil Armstrong placed his foot firmly on the fine-grained surface of the moon. The time was 10: 56 pm, July 20,1969.
单选题The puritan army executed the king, abolished the House of Lords, got the House of Commons to ______ England a "commonwealth", or republic.
单选题
There are many benefits to using online
distance learning environments. Online education is available any place, any
time for global communities of learners based on shared interests. Online
education with its group-based instruction and computer mediated communication
provides an opportunity for new development and understanding in teaching and
learning. Computer mediated communication encourages collaborative learning by
not providing cues regarding appearance, race, gender, education, or social
status, bestowing a sort of anonymity to participants. Distance also permits the
expression of emotion (both positive and negative) and promotes discussion that
normally would be inhibited. Yet, this same text-based positive
aspect of online learning makes online education more cumbersome and therefore
takes more time than face-to-face learning. In addition, the sheer bulk of
messages can be overwhelming. The learner 0nly has the written text and no other
non-verbal cues. This may confuse the learner and cause misunderstanding. Some
students are not willing to take the time to go in and look up homework
assignments and other online learning activities. ESL students shy away from
online classes. They have expressed fear of having their work, viewed by
others. In the road to dotcom in education, educators "have to
slow down from their busy lives to be free to focus first on connecting with
learners and connecting them to learning before they end up feeling like they
are no longer using technology, but are being used by it". There
is pressure to keep up with the times as well as "a cost-of-entry issue
regarding technology in education. Without a certain level of technology
services and learning options, many students will not consider attending a
certain institution". Mark Milliron claims that "any technology has to
prove that it will ultimately improve or expand learning". This will come about
if educators "slow down, look around, and get on the road to dotcom—a place to
thoughtfully engage and explore all aspects of technology, good, bad, or
indifferent... A place with mindful focus on the people and passions that make
life worth living". Should online learning be an issue of
control or should students be convinced of its value as an authentic learning
tool? Fear and a threatening environment don't enhance learning according to
brain-based learning research. "How students feel about a learning
situation determines the amount of attention they devote to it." "Positive
emotions ensure that learning will be retained." It's very. important to discuss
with students how they feel about technology and online learning so that they
feel good about what they are doing. The process of implementing
online distance learning is a slow and delicate one. Change will eventually come
about but it will take time.
单选题How is virtual reality surgery performed?
单选题The doctor pondered for a while, trying to recall which of several medications would be best to ______ the patient's suffering.
单选题
The need for solar electricity is
clear. It is safe, ecologically sound, efficient, continuously available, and is
has no moving parts. The basic problem with the use of solar photovoltaic
devices is economics, but until recently very little progress has been made
toward the development of low-cost photovoltaic devices. The larger part of
research funding has been devoted to study of single-crystal silicon solar
cells, despite the evidence, including that of the leading manufacturers of
crystalline silicon, that the technique holds little promise. The reason for
this pattern is understandable and historical. Crystalline silicon is the active
element in the Very successful semiconductor industry, and virtually all of the
solid state devices contain silicon transistors and diodes. Crystalline silicon,
however, is particularly unsuitable to terrestrial solar cells.
Crystalline silicon solar cells work well and are successfully used in the
space program, where cost is not an issue. While single-crystal silicon has been
proven in extraterrestrial use with efficiencies as high as 18 percent, and
other more expensive and scarce materials such as gallium arsenide can have even
higher efficiencies, costs must be reduced by a factor of more than 100 to make
them practical for commercial use. Beside the fact that the starting crystalline
silicon is expensive, 95 percent of it is wasted and does not appear in the
final device. Recently, there have been some imaginative attempts to make
polycrystalline and ribbon silicon, which are lower in cost than high-quality
single crystals. But to date the efficiencies of these apparently lower-cost
arrays have been unacceptably small. Moreover, these materials are cheaper only
because of the introduction of disordering in crystalline semiconductors, and
disorder degrades the efficiency of crystalline solar cells.
This dilemma can be avoided by preparing completely disordered or
amorphous materials. Amorphous materials have disordered atomic structure as
compared to crystalline materials. That is, they have only short-range order
rather than the long-range periodicity of crystals. The advantages of amorphous
solar cells are impressive. Whereas crystals can be grown as wafers about four
inches in diameter, amorphous materials can be grown over large areas in a
single process. Whereas crystalline silicon must be made 200 microns thick to
absorb a sufficient, amount of sunlight for efficient energy conversion, only 1
micron of the proper amorphous materials is necessary. Crystalline silicon solar
cells cost in excess of $100 per square foot, but amorphous films can be created
at a cost of about 50 per square foot. Although many scientists
were aware of the very low cost of amorphous solar cells, they felt that they
could never be manufactured with the efficiencies necessary to contribute
significantly to the demand for electric power. This was based on a
misconception about the feature which determines efficiency. For example, it is
not the conductivity of the material in the dark which is relevant, but only the
photoconductivity, that is the conductivity in the presence of sunlight.
Already, solar cells with efficiencies well above 6 percent have been developed
using amorphous materials, and further research will doubtless find even less
costly amorphous materials with higher
efficiencies.
单选题Although we have badly fouled our planetary next, ______, it is by no means clear that our profligacy has as yet greatly changed the incidence of cancer.
单选题Our school ______ a big library, several up-to-date laboratories and a fine swimming pool.
单选题Surprisingly enough, modern historians have rarely interested themselves in the history of the American South in the period before the South began to become self-consciously and distinctively "Southern" —the decades after 1815. Consequently, the cultural history of Britain's North American empire in the seventeenth and eighteenth centuries has been written almost as if the Southern colonies had never existed. The American culture that emerged during the Colonial and Revolutionary eras has been depicted as having been simply an extension Of New England Puritan culture. However, Professor Davis has recently argued that the South stood apart from the rest of American society during this early period, following its own unique pattern of cultural development. The case for Southern distinctiveness rests upon two related premises: first, that the cultural similarities among the five Southern colonies were far more impressive than the differences, and second, that what made those colonies alike also made them different from the other colonies. The first, for which Davis offers an enormous amount of evidence, can be accepted without major reservations; the second is far more problematic. What makes the second premise problematic is the use of the Puritan colonies as a basis for comparison. Quite properly, Davis decries the excessive influence ascribed by historians to the Puritans in the formation of American culture. Yet Davis inadvertently adds weight to such ascription by using the Puritans as the standard against which to assess the achievements and contributions of Southern colonials. Throughout, Davis focuses on the important, and undeniable, differences between the Southern and Puritan colonies in motives for and patterns of early settlement, in attitudes toward nature and Native Americans, and in the degree of receptivity to metropolitan cultural influences. However, recent scholarship has strongly suggested that those aspects of early New England culture that seem to have been most distinctly Puritan, such as the strong religious orientation and the communal impulse, were not even typical of New England as a whole, but were largely confined to the two colonies of Massachusetts and Connecticut. Thus, what in contrast to the Puritan colonies appears to Davis to be peculiarly Southern—acquisitiveness, a strong interest in politics and the law, and a tendency to cultivate metropolitan cultural models—was not only more typically English than the cultural patterns exhibited by Puritan Massachusetts and Connecticut, but also almost certainly characteristic of most other early modern British colonies from Barbados north to Rhode Island and New Hampshire. Within the larger framework of American colonial life, then, not the Southern—but the Puritan 'colonies appear to have been distinctive, and even they seem to have been rapidly assimilating to the dominant cultural patterns by the late Colonial period.
单选题After being defeated they{{U}} submitted {{/U}}to the enemy.
单选题The other distinguishing trait of the law is ______.
单选题They hit only the smaller people like me, while the politicians will of course ______it with money. A. do away with B. take away with C. make away with D. get away with
单选题If you make a cat angry, it may ______you.
