问题 选择题

下列对我国部分资源分布的分析正确的是

    ①我国北方多煤和石油,南方多铁矿和煤

    ②北方平原多、热量少、水分少;南方平原少、热量多、水分多

    ③西北干旱、多风沙、光照少;西南湿润、纬度低、光照强

    ④青藏高原地势高、气温低,草场资源和太阳能丰富 [ ]

A、①②

B、①③

C、②③

D、②④

答案

答案:D

单项选择题

When researchers come up with a new treatment that makes us feel or work better, it’s usually not just the truly sick who end up going in for an upgrade. The progress in developing treatments for illnesses that ravage memory and thought raises an important question: might the same tools be used to improve the functioning of minds that by most standards are already running fairly smoothly We may well be approaching an era of designer brains, in which those of us feeling a little foggy or dull can have our IQ, fast recall, and self-confidence inflated up via the prescription pad. "Some brain-related conditions we think of as ordinary, "says one researcher, "may eventually become disorders, too"—including perhaps less-than-razor-sharp thinking.
The notion of a prescription IQ lift is hardly new. According to polls, about one in 20 college students, and higher percentages of professors, already illicitly pop some form of Ritalin or Modafinil—legitimately prescribed for attention-deficit disorder and narcolepsy (嗜睡症), respectively—to augment alertness, concentration, and memory. But these drugs have proved only mildly effective on normal minds, and carry potentially severe side effects ranging from addiction to overstimulation.
Scientists had originally hoped that the decoding of the human genome would lead quickly to small groups of genes that control major mental disorders and traits, be they Alzheimer’s disease (老年痴呆症), intelligence, or personality. That hasn’t been the case; individual genes turn out in most cases to only weakly affect the brain, with most illnesses emerging from the interaction of large, complex networks of hundreds of genes.
That challenge hasn’t kept researchers from tracking down many of the genes in these networks to chip away at the genetic roots of mental disorders—and to come up with possible treatments based on some of those findings. The result is that medicine may allow us to challenge our genetic inheritance and repair environmental insults to the brain, whether as Alzheimer’s sufferers or just moody, forgetful people and hazy thinkers. Techniques undergoing testing now include altering genes within brain cells, or even pushing genes into creating altogether new brain cells. Neurologix in Fort Lee, New Jersey, for example, is developing brain-related gene therapies, which involve injecting harmless viruses that insert custom-built genes into cells. Though other experimental gene therapies have in the past often caused severe and even fatal side effects, Neurologix hopes to avoid them by targeting the viruses only at those cells that need repairing.
In Fact, We won’t necessarily have to turn to these more radical therapies to sharpen our thinking. The genetic and other new scientific insights into the brain are also helping to point the way to new drugs targeted at brain disorders— drugs that may also end up being taken as smart drugs by many of us without serious disorders.

What does the first sentence of the passage imply

A.Researchers always bring forth new and upgraded cures for illness.

B.Sick people are anxiously looking forward to new treatments.

C.Normal people tend to use the new treatment to be healthier.

D.New and upgraded treatment should make us feel or work better.

单项选择题