A British study found that B vitamins could reduce brain shrinkage in older people with mild memory loss. It showed that B vitamins caused an average one-third reduction in brain shrinkage among adults who had trouble in remembering. Retired Oxford University pharmacology(药理学)professor David Smith was a leader of the study. He praised the use of the vitamins as simple and safe. He also said researchers do not yet know if B vitamins could prevent or slow Alzheimer's disease(老年痴呆症). Vitamins are important for good health. These complex organic substances help to carry out chemical changes within cells. If we do not get enough of the vitamins we need in our food, we are at risk of developing a number of diseases. Some shrinkage of the brain is thought to happen normally as people grow older. Yet studies have shown a link between a larger shrinkage and Alzheimer's disease. The Oxford researchers say about one in six people over age seventy has problems with mental operations. They say half of these people develop serious loss of mental ability, as in Alzheimer's disease. Over time, the disease robs people of their memories. Finally, it takes away their ability to care for themselves.
单选题 According to the British study, B vitamins can help people who have trouble in______.
【正确答案】 B
【答案解析】解析：事实细节题。由题干中的British study定位到文章第一段。该段提到，B族维生素可以帮助有记忆问题的成年人平均减少三分之一的大脑萎缩，由此可知B族维生素可以帮助记忆有问题的人，故正确答案为B)。
单选题 Professor David Smith said that the effect of B vitamins on Alzheimer's disease is______.
【正确答案】 D
【答案解析】解析：细节推断题。由题干中的Bvitamins，Alzheimer’s disease定位到文章第二段末句。定位句提到，研究人员还不知道B族维生素能否预防或减缓老年痴呆症，由此可以推断目前尚不明确B族维生素对老年痴呆症的疗效，故D)为正确答案。A)“积极的”、B)“消极的”和C)“决定性的”不符合文意。
单选题 According to the third paragraph, vitamins can help our cells to deal with______.
【正确答案】 B
【答案解析】解析：事实细节题。由题干中的thethird paragraph，vitamins和cells定位到文章第三段第一、二句。定位句提到，维生素对健康很重要，这些复杂的有机物质能够帮助细胞内部进行化学变化。由此可知，维生素能够帮助细胞进行化学变化，故正确答案为B)。A)“有机物质”指的是维生素本身，C)“心理疾病”和D)“食品风险”均与维生素本身的功能无关。
单选题 It is possible that as we grow older, our brains will______.
【正确答案】 B
【答案解析】解析：细节推断题。由题干中的growolder和brains定位到文章倒数第二段首句。定位句提到，大脑会随着人们的年龄增长而自然萎缩。因此本题应当选B)“在某种程度上会萎缩”。A)“没有变化”、C)“急剧发育”和D)“突然消失”不符合文意。
单选题 According to the passage, how many people over seventy suffer serious loss of mental ability?
【正确答案】 D
【答案解析】解析：推理判断题。由题干中的people over seventy和loss of mentalability定位到文章最后一段第一、二句。该段第一句提到，70岁以上的人中有大约六分之一在智力活动方面存在问题，第二句又说其中又有一半出现了很严重的智力损失，因此应当是70岁以上的人中有十二分之一出现了很严重的智力损失，故选D)。