单选题A survey was carried out on death rate of new-born babies in that region,______were surprising.

单选题Of the following writers______is not influenced by naturalistic writing.

单选题As Gilbert White, Darwin, and others observed long ago, all species appear to have the innate capacity to increase their numbers from generation to generation. The task for ecologists is to untangle the environmental and biological factors that hold this intrinsic capacity for population growth in check over the long run. The great variety of dynamic behaviors exhibited by different populations makes this task more difficult; some populations remain roughly constant from year to year; others exhibit regular cycles of abundance and scarcity; still others vary wildly, with outbreaks and crashes that are in some cases plainly correlated with the weather, and in other cases not. To impose some order on this kaleidoscope of patterns, one school of thought proposes dividing populations into two groups. These ecologists posit that the relatively steady populations have "density-dependent" growth parameters; that is, rates of birth, death, and migration which depend strongly on population density. The highly varying populations have "density-independent" growth parameters, with vital rates buffeted by environmental events; these rates fluctuate in a way that is wholly independent of population density. This dichotomy has its uses, but it can cause problems if taken too literally. For one thing, no population can be driven entirely by density-independent factors all the time. No matter how severely or unpredictably birth, death and migration rates may be fluctuating around their long-term averages, if there were no density-dependent effects, the population would, in the long run, either increase or decrease without bound(barring a miracle by which gains and losses canceled exactly). Put another way, it may be that on average 99 percent of all deaths in a population arise from density-independent causes, and only one percent from factors varying with density. The factors making up the one percent may seem unimportant, and their cause may be correspondingly hard to determine. Yet, whether recognized or not, they will usually determine the long-term average population density. In order to understand the nature of the ecologist"s investigation, we may think of the density-dependent effects on growth parameters as the "signal" ecologists are trying to isolate and interpret, one that tends to make the population increase from relatively low values or decrease from relatively high ones, while the density-independent effects act to produce "noise" in the population dynamics. For populations that remain relatively constant, or that oscillate around repeated cycles, the signal can be fairly easily characterized and its effects described, even though the causative biological mechanism may remain unknown. For irregularly fluctuating populations, we are likely to have too few observations to have any hope of extracting the signal from the overwhelming noise. But it now seems clear that all populations are regulated by a mixture of density-dependent and density-independent effects in varying proportions.

单选题Which of the following is the correct description of the English consonant[z]?

单选题The proverb "Modest dogs miss much meat" exemplifies the use of______.

单选题During language acquisition, children go through several stages, during which stage they begin to have sensitivity to the phonetic distinctions used in their parents' language.

单选题So he could not resist the temptation to A play a little joke on the education system, which B had been thrown into C such a panic by the D successfully launching of the Russian Sputnik.

单选题The doctors who serve the community in general health care in Britain, rather like solicitors of the medical profession, who usually join together in partnership in a medical practice, must study for seven years and pass exams before they become qualified______.

单选题The word "schism" (Line 3, Paragraph 1) in the context probably means ______.

单选题The central character J. Alfred Prufrock in T. S. Eliot" s famous poem The Love Song of J. Alfred Prufrock is .______.

单选题In order to raise money, his mother had to______with some of her most treasured possessions.

单选题Which one is different from the others according to places of articulation?

单选题______ involves the comparison of two concepts in that one is construed in terms of the other.

单选题Of manners of articulation, ______ is complete closure of the articulators involved so that the airstream cannot escape through the mouth.

单选题Which is NOT a form of sound patterning?

单选题Tower C of Office Park, a dazzling new office building in Beijing"s Central Business District, has been widely praised in the market for its superior quality and pleasant amenities after it was unveiled to the market at a press conference held in March 2010.

单选题______refers to a marginal language of few lexical items and straight forward grammatical rules, used as a medium of communication.

单选题We must all hang together or assuredly we will all hang separately.

单选题Christie stared angrily at her boss and turned away, as though ______ out of the office.

单选题{{B}}Text 3{{/B}} During the past generation, the American middle-class family that once could count on hard work and fair pay to keep itself financially secure has been transformed by economic risk and new realities. Now a pink slip, a bad diagnosis, or a disappearing spouse can reduce a family from solidly middle class to newly poor in a few months. In just one generation, millions of mothers have gone to work, transforming basic family economics. Scholars, policymakers, and critics of all stripes have debated the social implications of these changes, but few have looked at the side effect: family risk has risen as well. Today's families have budgeted to the limits of their new two-paycheck status. As a result, they have lost the parachute they once has in times of financial setback-- a back-up earner (usually Mom) who could go into the workforce if the primary earner got laid off or fell sick. This "added-worker effect" could support the safety net offered by unemployment insurance or disability insurance to help families weather bad times. But today, a disruption to family fortunes can no longer be made up with extra income from an otherwise-stay-at-home partner. During the same period, families have been asked to absorb much more risk in their retirement income. Steelworkers, airline employees, and now those in the auto industry are joining millions of families who must worry about interest rates, stock market fluctuation, and the harsh reality that they may outlive their retirement money. For much of the past year, President Bush campaigned to move Social Security to a savings-account model, with retirees trading much or all of their guaranteed payments for payments depending on investment returns. For younger families, the picture is not any better. Both the absolute cost of healthcare and the share of it borne by families have risen--and newly fashionable health-savings plans are spreading from legislative halls to Wal-Mart workers, with much higher deductibles and a large new dose of investment risk for families' future healthcare. Even demographics are working against the middle class family, as the odds of having a weak elderly parent-- and all he attendant need for physical and financial assistance -- have jumped eightfold in just one generation. From the middle-class family perspective, much of this, understandably, looks far less like an opportunity to exercise more financial responsibility, and a good deal more like a frightening acceleration of the wholesale shift of financial risk onto their already overburdened shoulders. The financial fallout has begun, and the political fallout may not be far behind.