問題詳情

請依下文回答第 31 題至第 35 題： Experiments that go according to plan can be useful. But the biggest scientific advances often emerge fromthose that do not. Such is the case with a study just reported in the Proceedings of the National Academy ofSciences. When they began it, Hector DeLuca of the University of Wisconsin, Madison, and his colleagues hadbeen intending to examine the effects of ultraviolet (UV) light on mice suffering from a rodent version of multiplesclerosis (MS). By the project’s end, however, they had in their hands two substances which may prove valuabledrugs against the illness. Multiple sclerosis is an autoimmune disease. This means it is caused by a victim’s immune system turningon and destroying parts of his own body. In the case of MS the targets of these attacks, which may continue foryears, are the fatty sheaths that insulate nerve cells and thus help nervous impulses to propagate. People sufferingfrom MS are often weakened, and sometimes physically disabled by it, and may also become blind. What drives the immune system to behave in this way remains mysterious, but in the 1970s researchersuncovered a promising clue when they noticed that MS is rarer near the equator than it is at high latitudes. Thefirst hypothesis proposed to explain this observation was that vitamin D (a substance created by sunlight’s actionon precursor molecules in the skin) might be helping to prevent MS. That made sense, since those living in thetropics receive more sunlight than those in temperate zones. Sadly, follow-up experiments failed to support thenotion. Those experiments did, though, lead Dr. DeLuca to discover that the preventive effect is associated with aparticular sort of sunlight—UV with a wavelength of between 300 and 315 nanometres (billionths of a metre). Hislatest experiment was intended to dig deeper into this observation, by using this type of light to irradiate mice thathad been injected with chemicals known to cause the rodent equivalent of MS.
31 According to the passage, what can we know of Dr. DeLuca’s project?
(A)It aims to treat MS patients at high latitudes.
(B)It leads to results different from the team’s expectation.
(C)It involves vitamin D’s effect on UV prevention.
(D)It involves mice suffering from the effects of ultraviolet (UV) light.

參考答案

答案：B
難度：非常困難0.166667
統計：A(1),B(1),C(2),D(2),E(0)

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