单项选择题

Bacteria are terribly good for you. So say the promoters of a rapidly growing industry in "probiotic" products. The title "probiotic" (for life) is technically reserved for those food products containing living cultures of "good" microorganisms. Just how good are they It depends on to whom you are listening.
"Microbic marketing" is highly competitive; many brands of yogurts, many yogurt drinks, and many capsules of live bacteria are on display -all promising to be good for you ! Promotions are intense, and the questions are many. Do healthy people need cultures of bacteria when they already have a crowd of fine bacteria at work How valid are the claims that probiotic products increase the health of intestinal cells, degrade toxins, or prevent cancer There is yet no scientific consensus, and for now, consumers must decide for themselves.
The recent interest in probiotic products has grown out of a concern for the side effects of antibiotics in the 1950s. Since antibiotics are not very selective as to which bacteria they attack, those prescribed for a toothache can quickly wipe out a whole population of intestinal microbes. Bacteria contained in fermented-milk products appeared to be effective in restoring populations of the beneficial bacteria after such a catastrophe. In the development of probiotic products, different species of Lactobacilli and Bifidobacteria are selected according to their abilities to produce yogurt, to survive passage through the digestive tract, and to establish themselves in their new environment by out-competing potentially unfriendly microbes for space and nutrients. This last criterion is not always easy to measure.
Cultures of yogurt must contain at least 100 million live bacteria per gram. It’s a big number, but it is impossible to know how many will loiter in your digestive system. Research now is underway to determine whether probiotic products might take the place of controversial antibiotics in livestock feed, or if bacterial/antibacterial compounds might be useful as food preservatives. Probiotics is about using bacteria to control other bacteria!
Which of the following is NOT cited as an example of invalid sales promotions

A. There is yet no scientific consensus on the questions about "probiotic" products.
B. Antibiotics are not very selective as to which bacteria they attack.
C. It is impossible to know how many live bacteria will be preserved in the digestive system.
D. It is not always easy to measure to what extent probiotic products can outrun potentially unfriendly microbes.
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单项选择题
Which of the following statements is NOT true A. White-collar workers are also fired in large numbers. B. Last year’s U. S. economical growth was very impressive. C. Companies with rising productivity used to raise wages to keep labor. D. Self-employment was a way out for the American economy.
Americans have so far responded to their failing fortunes by working harder. American males now toil about a week and a half longer than they did in 1973, the first time this century working hours have increased over an extended period of time. Women, particularly in poorer families, are working harder, too. Two-worker families rose by more than 20 percent in the 1980s. Seven million workers hold at least two jobs, the highest proportion in half a century.America is simply not growing fast enough to tighten the labor market and push up real wages. The danger of the information age is that while in the short run it may be cheaper to replace workers with technology, in the long run it is potentially self-destructive because there will not be enough purchasing power to grow the economy.
To avoid this dismal prospect, we must get on the virtuous cycle of higher growth and avoid the vicious cycle of retrenchment. Otherwise, an angry, disillusioned and frustrated population—whose rage today is focused on big government, excess taxes, immigration, welfare and affirmative action--may someday be brought together by its sense of diminished hopes. Then we will all be in for a very difficult time.