题目

阅读理解 Researchers at the University of Texas Southwestern Medical Center mapped brain changes after a year of aerobic workouts and uncovered a potentially significant process: Exercise increases blood flow into two key areas of the brain associated with memory. The study, published in the Journal of Alzheimer's Disease, showed this blood flow can help even older people with memory issues improve cognition, a finding that could guide future Alzheimer's disease research, according to UT Southwestern Medical Center. In the study, researchers followed 30 participants who were 60 or older and had memory problems. Half experienced a year of aerobic exercise while the other half did stretches. "We've shown that even when your memory starts to fade, you can still do something about it by adding aerobic exercise to your lifestyle," said Binu Thomas, a senior research scientist of UT Southwestern Medical Center who led the study. "The aerobic exercise group showed a 47% improvement in some memory scores after a year; the other group showed slight change. Brain imaging of the aerobic exercise group, taken while at rest at the beginning and end of the study, showed increased blood flew into the specific brain areas that played important roles in memory function." Many teams across the world are trying to determine if aerobic exercise might fight memory loss. Evidence is growing that it could at least play a small role in delaying or reducing the risk of Alzheimer's disease. For example, a 2018 study showed that people with lower fitness levels experienced faster retrogression of vital nerve fibers in the brain called white matter related to memory. "Blood flow in the brain connected with memory improvement is still a part of the puzzle, and we need to continue piecing it together," Thomas says. "But we've seen enough date to know that starting a fitness program can have lifelong benefits for our brains as well as our hearts." （1） What is the study mainly about? A . Old people have memory issues. B . Exercise improves memory. C . Aerobic workouts benefit mental health. D . Alzheimer's disease can be cured. （2） What happened to participants after one-year aerobic exercise? A . Earlier memories were refreshed. B . Memory scores showed very small change. C . Brain imaging remained the same. D . More blood flew into memory-related areas. （3） What does the underlined word "retrogression" mean in the fourth paragraph? A . Growth. B . Recovery. C . Decline. D . Extension. （4） What can be inferred from the last paragraph? A . Further research work requires doing. B . More people experience memory loss. C . Mystery of brain blood flow has been solved. D . Signs of memory loss can be discovered earlier. 答案： B D C A

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