Question

    We already know that exercise is good for our bodies. Daily exercise fights the loss of muscle tone and flexibility that tends to increase slowly with age. And it turns out that it has the same fountain-of-youth effects on our brains.

Studies show that over time our minds also become less nimble. We lose the ability to process new information or switch between mental tasks quickly — and now we know why.

A recent study examined nearly 100 individual studies on exercise and brain function and discovered exercising an average of 52 hours over six months is “associated with improved cognitive (认知的) performance in older adults with and without cognitive damage.” The type of exercises that are beneficial include aerobic, strength-training and mind-body exercises like yoga or tai chi.

In previous studies, researchers from Japan’s University of Tsukuba wanted to explore this idea by looking at the effect of exercise on the weakening of the brain. They tested the oxygen ability of 60 Japanese men between the ages of 64 and 75 who did not show any signs of dementia (痴呆) or other mental symptoms. Next, they looked at the brain activity of each man as he completed a mental task. They found that the fitter a participant was, the less brain power he used to complete the tasks when compared with his out-of-shape peers, which made him more efficient.

Although much research is focused on how exercise may benefit an aging brain, exercise offers brain health benefits at almost any age, and this includes children. A review of 14 studies showed that more physically active schoolchildren do better academically. Exercise actually causes your brain to grow in size. So get moving and keep moving for best results.

1.The underlined word “nimble” in Paragraph 2 most probably means__________.

A.dull-witted B.single-minded

C.absent-minded D.quick-witted

2.What can we infer about the participants’ less-active peers?

A.They had significant brain advantages.

B.Their brains were younger than their age.

C.Their cognitive performance would decline.

D.They had a quick mind when doing the task.

3.How does the author support his idea?

A.By making comparisons.

B.By analyzing study results.

C.By describing the processes.

D.By telling peers’experiences.

4.What’s the main idea of the text?

A.Exercise is beneficial for your bodies.

B.Exercise can benefit your brain health.

C.Exercise is especially good for dementia.

D.Exercise may lower your risk of mental problems.

Answer

1.D

2.C

3.B

4.B

【解析】

本文是说明文。锻炼可以应对肌肉张力和灵活性的丧失，同样锻炼也能使大脑保持年轻。本文通过介绍多项研究结果，阐述了锻炼也能让我们的大脑健康受益这一观点。

1.

词句猜测题。第一段提到，肌肉的张力和灵活性往往随着我们变老而增长缓慢。此处作类比，指随着时间的推移我们的思维也变得不那么灵活和敏捷。quick-witted “机智灵敏的”与nimble词义匹配。故选D。

2.

推理判断题。根据第四段最后一句They found that the fitter a participant was, the less brain power he used to complete the tasks when compared with his out-of-shape peers, which made him more efficient.可知，他们发现，与身材走样的同伴相比，身体越健康的参与者完成任务时所使用的脑力就越少，这使得他的效率更高。即与身材不佳的同龄人相比，实验参与者身体越健康，他们的认知能力就越强。由此推知，锻炼少的人，其认知能力就会衰弱。故选C。

3.

推理判断题。根据第三段“A recent study”、第四段“In previous studies”及最后一段“A review of 14 studies”部分可看出，作者是通过分析这些研究的结果来支撑其观点的。故选B。

4.

主旨大意题。本文主要通过介绍多项研究结果，阐述了锻炼也能让我们的大脑健康受益这一观点。根据文中的关键句“... and now we know why.”和“Exercise actually causes your brain to grow in size.”可知，本文的主题为“运动有益于你的大脑健康。”故选B。