OG 11 V22

xingxc11

Half of the subjects in an experiment—the experimental group—consumed large quantities of a popular artificial sweetener. Afterward, this group showed lower cognitive abilities than did the other half of the subjects—the control group—who did not consume the sweetener. The detrimental effects were attributed to an amino acid that is one of the sweetener’s principal constituents.

Which of the following, if true, would best support the conclusion that some ingredient of the sweetener was responsible for the experimental results?

(A)    Most consumers of the sweetener do not consume as much of it as the experimental group members did.
(B)    The amino acid referred to in the conclusion is a component of all proteins, some of which must be consumed for adequate nutrition.
(C)    The quantity of the sweetener consumed by individuals in the experimental group is considered safe by federal food regulators.
(D)    The two groups of subjects were evenly matched with regard to cognitive abilities prior to the experiment.
(E)    A second experiment in which subjects consumed large quantities of the sweetener lacked a control group of subjects who were not given the sweetener.

这道题选D 请诸位帮忙分析一下吧 我选的B

dongkailin

D选项排除他因，也就是控制变量啦~确认实验者的认知能力一致才能更准确得出之后的变化是SWEETENER所造成的。B是无关选项，不要看到AMINO在之前出现就激动了哦~~还是要找到结论和前提再做判断