题目内容

糖尿病患者控制饮食的目的

A. 控制血糖,减轻胰岛素B细胞的负担
B. 减轻体重,防止肥胖
C. 减少胰液分泌
D. 延缓消化道吸收
E. 减慢肠蠕动,防止腹泻

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诊断胃癌可靠的方法是

A. 消化道钡餐
B. 胃B超
C. 大便隐血阳性
D. 纤维胃镜及活组织检查
E. 胃CT检查

急性心肌梗死发生心室颤动的先兆是

A. 房性早搏
B. 室性早搏频发、成对、多源出现
C. 室上性阵发性心动过速
D. 心房纤颤
E. 房室传导阻滞Ⅱ度

Text 2Standard & Poor’s maintains a cautious stance on cable-TV operators in the wake of Verizon’s (VZ) announcement in early May of aggressive price cuts for its digital subscriber line (DSL) Internet-access service. Our overall outlook for the S & P Cable & Broadcasting index, which also includes shares of over-the-air TV and radio broadcasters, is neutral to modestly positive. Cable operators have so far ruled out an overt price war on broadband services. However, expect to see near-term responses like increased bundling of services, extended free months, more aggressive marketing and promotions, even modest price cuts from cable outfits that offer multiple services such as broadband as they defend their high growth Internet-access business.Continued rapid growth in digital cable and high-speed data services helped support the industry’s ongoing revenue growth. We at S & P are wary of price pressures on the long-term and short-term economies of cable’s broadband business. That’s especially true as another Baby Bell, SBC Communications (SBC), is also undercutting cable-service providers in many core markets.In their traditional business segment, U.S. cable operators continue to benefit from a modest rebound in advertising spending, following a significant downturn during the economic slump that started in 2001. The industry has actually increased its share of total U. S. ad spending. The cable sector posted uninterrupted revenue growth during the recent downturn, as its greater reliance on subscriber revenues gives it a more defensive posture than broadcasters. Subscriptions remain the industry’s primary revenue source, accounting for roughly 65% of the total, with advertising makes up the rest.Our near-term outlook for cable remains tempered by heightened levels of geopolitical anxieties, though the Iraq war’s end has alleviated their impact on advertising demand. Meanwhile, core subscription growth continues to be driven by robust rates of high-speed data sign-ups and by improved prospects for digital-video ancillary offerings like video-on-demand and high-definition TV.We believe that successful media operators will continue to anticipate, rather than react to, the ever-changing dynamics of an increasingly competitive media environment. Even with increased regulatory surveillance, vertically and horizontally integrated media operators should begin to wield increasing competitive advantages as they leverage operating efficiencies and realize synergies across multiple delivery platforms. Which of the following will help create a bright outlook for cable()

A. higher levels of geopolitical anxieties
B. prospects of intensive competition
C. war's impact on advertising demand
D. vigorous rates of high-speed data sign-ups

Text 4Although, recent years have seen substantial reductions in noxious pollutants from individual motor vehicles, the number of such vehicles has been steadily increasing. Consequently, more than 100 cities in the U. S. still have levels of carbon monoxide, particulate matter, and ozone that exceed legally established limits. There is a growing realization that the only effective way to achieve further reduction in vehicle emissions—short of a massive shift away from the private automobile—is to replace conventional diesel fuel and gasoline with cleaner-burning fuel such as compressed natural gas, liquefied petroleum gas, ethanol, or methanol.All of these alternatives are carbon-based fuels whose molecules are smaller and simpler than those of gasoline. These molecules burn more cleanly than gasoline, in part because they have fewer, if any, carbon-carbon bonds, and the hydrocarbons they do emit are less likely to generate ozone. The combustion of larger molecules, which have multiple carbon-carbon bonds, involves a more complex series of reactions. These reactions increase the probability of incomplete combustion and are more likely to release uncombusted and photochemically active hydrocarbon compounds into the atmosphere. On the other hand, alternative fuels do have drawbacks. Compressed natural gas would require that vehicles have a set of heavy fuel tanks—a serious liability in terms of performance and fuel efficiency—and liquefied petroleum gas faces fundamental limits on supply.Ethanol and methanol, on the other hand, have important advantages over other carbon based alternative fuels., they have a higher energy content per volume and would require minimal changes in the existing network for distributing motor fuel. Ethanol is commonly used as a gasoline supplement, but it is currently about twice as expensive as methanol, the low price of which is one of its attractive features. Methanol’s most attractive feature, however, is that it can reduce by about 90 percent the vehicle emissions that form ozone, the most serious urban air pollutant.Like any alternative fuel, methanol has its critics. Yet much of the criticism is based on the use of "gasoline alone" vehicles that do not incorporate even the simplest design improvements that are made possible with the use of methanol. It is true, for example, that a given volume of methanol provides only about one-half of the energy that gasoline and diesel fuel do, other things being equal, the fuel tank would have to be somewhat larger and heavier. However, since methanol-fueled vehicles could be designed to be much more efficient than "gasoline alone" vehicles fueled with methanol, they would need comparatively less fuel. Vehicles incorporating only the simplest of the engine improvements that methanol makes feasible would still contribute to an immediate lessening of urban air pollution. The author is primarily concerned with ()

A. countering a flawed argument that dismisses a possible solution to a problem
B. reconciling contradictory points of view about the nature of a problem
C. identifying the strengths of possible solutions to a problem
D. discussing a problem and arguing in favor of one solution to it

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