考研考试

【单选题】Mark Twain once observed that giving up smoking is easy. He knew, because he’d done it hundreds of times himself. Giving up for ever is a trifle more difficult, apparently, and it is well known that it is much more difficult for some people than for others. Why is this so
Few doctors believe any longer that it is simply a question of will power.And for those people that continue to view addicts as merely "weak", recent genetic research may force a rethink.A、study conducted by Jacqueline Vink, of the Free University ofAmsterdam, used a database called the Netherlands Twin Register to analyse the smoking habits of twins. Her results suggest that an individual’s degree of nicotine dependence, and even the number of cigarettes he smokes per day, are strongly genetically influenceD、
The Netherlands Twin Register is a voluntary database that is prized by geneticists because they allow the comparison of identical twins (who share all their genes) with fraternal twins (who share half). In this case, however,Dr. Vink did not make use of that fact. For her, the database was merely a convenient repository of information. Instead of comparing identical and fraternal twins, she concentrated on the adult fraternal twins, most of whom had completed questionnaires about their habits, including smoking, and 536 of whom had givenDNA、samples to the register.
The human genome is huge. It consists of billions ofDNA、"letters", some of which can be strung together to make sense (the genes), but many of which have either no function, or an unknown function. To follow what is going on, geneticists rely on markers they have identified within the genome. These are places where the genetic letters may vary between individuals. If a particular variant is routinely associated with a particular physical feature or a behaviour pattern, it suggests that a particular version of a nearby gene is influencing that feature or behaviour.
Dr. Vink hopes that finding genes responsible for nicotine dependence will make it possible to identify the causes of such dependence. That will help to classify smokers better (some are social smokers while others are physically addicted) and thus enable "quitting" programmes to be customiseD、
Results such asDr. Vink’s must be interpreted with care.Association studies, as such projects are known, have a disturbing habit of disappearing, as it were, in a puff of smoke when someone tries to replicate them.But ifDr. Vink really has exposed a genetic link with addiction, then Mark Twain’s problem may eventually become a thing of the past.
Dr. Vink’s results must be interpreted with care becauseA．it may have negative effects on related studies.
B．it is unreliable so far.
C．it may provide an excuse for nicotine addicts.
D．it could undermine the anti-smoking movement.

网考网参考答案：B
网考网解析：
本题问为什么须慎重对待Dr.Vink的研究成果。末段“Association studies…have a disturbing habit of disappearing，as it were，in a puff of smoke when someone tries to replicate them，”可知类似的研究可重复性不稳定，也就是说这个实验目前也没有充分的证据。因此[B]“至今仍不可靠”正确。 [A]会对相关实验产生负面影响：文中只说相关实验可重复性不稳定，而没有说此实验会影响相关实验。 [C]会给瘾君子以吸烟的借口；[D]会削弱戒烟运动：Dr.Vink研究的成果很可能给瘾君子以借口从而破坏戒烟，但原文强调的不是因为结果可能带来的影响，而是结果本身的可靠性问题。 document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>