题目

director of the Alzheimer's Disease Research Center at Columbia University Medical Center. Small said that even more important, the new study offers the first direct evidence that memory deteriorates with age because of changes in the dentate gyrus(齿状圆),a region of the hippocampus(海马). Previous studies had shown a link between changes in this region of the brain and normal, age-related memory loss, but the Columbia University study asserts a causal link. The study involved 37 healthy subjects who ranged in age from 50 to 69. Researchers said that if a person had the memory of a typical 60-year-old at the beginning of the study, on average that person's memory would function more like a30-or 40-year-old's after three months of being given a high-flavanol diet, consuming 900 milligrams a day. Small said the typical candy bar contains only about 40m g of flavanols. The researchers also cautioned that more work is needed because of the study's small sample size. The compound appears to enhance connectivity and metabolic activity in the dentate gyrus. Aging appears to reduce the connections between neurons in that part of the brain. That decline, according to Small, however, is not related to severe memory loss and cell death in Alzheimer's disease or other dementias(痴呆). 4/5 34. Future research that serves as an improvement over the new study mentioned in the passage may be a study that _. A tests more 30-or 40-year-old subjects B lasts for a period longer than three months C uses a diet with a larger amount of chocolate D contains a larger number of older subjects

director of the Alzheimer's Disease Research Center at Columbia University Medical Center. Small said that even more important, the new study offers the first direct evidence that memory deteriorates with age because of changes in the dentate gyrus(齿状圆),a region of the hippocampus(海马). Previous studies had shown a link between changes in this region of the brain and normal, age-related memory loss, but the Columbia University study asserts a causal link. The study involved 37 healthy subjects who ranged in age from 50 to 69. Researchers said that if a person had the memory of a typical 60-year-old at the beginning of the study, on average that person's memory would function more like a30-or 40-year-old's after three months of being given a high-flavanol diet, consuming 900 milligrams a day. Small said the typical candy bar contains only about 40m g of flavanols. The researchers also cautioned that more work is needed because of the study's small sample size. The compound appears to enhance connectivity and metabolic activity in the dentate gyrus. Aging appears to reduce the connections between neurons in that part of the brain. That decline, according to Small, however, is not related to severe memory loss and cell death in Alzheimer's disease or other dementias(痴呆). 4/5 34. Future research that serves as an improvement over the new study mentioned in the passage may be a study that _. A tests more 30-or 40-year-old subjects B lasts for a period longer than three months C uses a diet with a larger amount of chocolate D contains a larger number of older subjects

题目解答

答案

问题解析

题目要求我们选择一个未来研究，该研究能够改进文中提到的新研究。文中提到的研究涉及37名年龄在50到69岁之间的健康受试者，研究持续了三个月，受试者每天摄入900毫克的黄烷醇。研究发现，这种高黄烷醇饮食可以改善记忆力，使受试者的记忆力从典型的60岁水平提升到30或40岁的水平。然而，研究人员也指出，由于样本量较小，需要更多的工作来验证这一发现。

选项分析

  • A. tests more 30-or 40-year-old subjects

    • 这个选项建议测试更多30或40岁的受试者。然而，文中提到的研究重点是50到69岁的受试者，因此增加30或40岁的受试者并不能直接改进现有研究的结论。

  • B. lasts for a period longer than three months

    • 这个选项建议研究持续时间超过三个月。虽然延长研究时间可以提供更多的数据，但并不是直接针对样本量小的问题。

  • C. uses a diet with a larger amount of chocolate

    • 这个选项建议使用含有更多巧克力的饮食。文中提到的是黄烷醇的摄入量，而不是巧克力的摄入量。因此，增加巧克力的摄入量并不一定能够改进研究。

  • D. contains a larger number of older subjects

    • 这个选项建议增加更多老年受试者。文中提到的研究样本量较小，只有37名受试者。增加样本量可以提高研究的统计显著性和可靠性，因此这是一个合理的改进方向。

最佳答案

根据上述分析，选项 D 是最合理的改进方向，因为它直接针对了文中提到的样本量小的问题。增加更多老年受试者可以提供更可靠的数据，验证高黄烷醇饮食对记忆力的改善效果。

最终答案

D. contains a larger number of older subjects

解析

本题考查对文章主旨的理解和逻辑推理能力。文章主要讨论了一项关于高黄烷醇饮食对老年人记忆改善的研究，指出其局限性在于样本量较小。因此，未来研究的改进方向应直接针对这一问题。解题关键在于抓住文章中提到的“more work is needed because of the study's small sample size”，从而推断出扩大样本量是核心改进点。

选项分析

A. tests more 30-or 40-year-old subjects

文章的研究对象是50-69岁的老年人，目标人群为已出现记忆衰退的中老年人。增加30-40岁受试者无法解决样本量小的问题，且该年龄段人群可能尚未出现显著记忆衰退，与研究目标无关。

B. lasts for a period longer than three months

研究周期延长虽能提供更多数据，但文章未提及研究时长是限制因素。延长周期无法直接解决样本量小导致的统计可靠性问题。

C. uses a diet with a larger amount of chocolate

文章明确指出关键变量是黄烷醇（900毫克/天），而非巧克力本身。增加巧克力摄入可能改变实验变量，无法保证效果，且黄烷醇含量因巧克力种类差异较大。

D. contains a larger number of older subjects

文章明确指出“small sample size”是研究局限性，扩大样本量（尤其是老年群体）能提高统计显著性，验证结果的可靠性。此选项直接回应了文章的不足，是最合理的改进方向。