《2025年一本英语五合一必刷题高中人教版》

Have you ever wondered why you might be shorter than your friends or family? Now scientists believe that humans' growing taller and reaching puberty(青春期) earlier are due to a sensor in the brain.
We already know that better nutrition leads to greater height as humans have been growing taller on the whole in recent centuries. Better nutrition also causes people to reach maturity faster. Genes also play a role in how tall we become. We have known these for a long time. But a new study suggests that a brain receptor—MC3R—could be responsible for our growth, too.
Joint research shows that MC3R is responsible for signals from food reaching a part of the brain called the hypothalamus(下丘脑). The hypothalamus is responsible for keeping things in check like body temperature and regulating appetite and weight.
Some children get to eat lots of food that makes them grow. Professor Sir Stephen O'Rahilly, one of the authors of the study, said, “The receptor tells the body, ‘We've got lots of food, so grow quickly and reach puberty soon.’ It's not just magic—we have the complete wiring diagram for how it happens.” MC3R not working properly tends to convey the opposite information, meaning that people are shorter and start puberty much later.
There is an awful lot about the brain we still do not know. But the findings of the research could lead to further development of drugs for children with delayed growth and puberty starting much later. More understanding of the receptor won't mean that we can make ourselves taller. That all still depends on genes, but it could help people with chronic(慢性的) illnesses who need to build up muscle.
“Future research should investigate if drugs that activate MC3R might help redirect calories into muscle and other tissues, with the prospect of improving the physical functionality of such patients,” O'Rahilly said.
12. Which factor's effect on height did the new study mainly focus on?
A. The genes.
B. The nutrition.
C. A brain receptor.
D. A brain signal.
13. What might MC3R tell the body when it doesn't function properly?
A. There is too much food.
B. There isn't enough food.
C. It's magic to reach puberty.
D. The hypothalamus isn't in good condition.
14. What can further understanding of MC3R help people do?
A. Cure chronic illnesses.
B. Grow taller and healthier.
C. Use drugs to improve genes.
D. Deal with children's delayed growth.
15. What does the underlined word “activate” in the last paragraph mean?
A. Block.
B. Collect.
C. Examine.
D. Stimulate.

答案： 12. C 细节理解题。根据第一段最后一句“Now scientists believe that humans’ growing taller and reaching puberty earlier are due to a sensor in the brain.”和第二段最后一句“But a new study suggests that a brain receptor—MC3R—could be responsible for our growth, too.”可知，这项新研究主要关注的是大脑中一种名为MC3R的脑受体对身高的影响。
13. B 推理判断题。根据第四段最后一句“MC3R not working properly tends to convey the opposite information, meaning that people are shorter and start puberty much later.”可知，MC3R功能异常时，会传达与功能正常时相反的信息。再根据该段中的“The receptor tells the body, ‘We’ve got lots of food, so grow quickly and reach puberty soon.’”可知，MC3R功能正常时，会发出“我们已经获得很多食物”的信号。由此可推知，MC3R功能异常时，可能会发出“没有足够的食物”这一信号。
14. D 细节理解题。根据倒数第二段第二句“But the findings of the research could lead to further development of drugs for children with delayed growth and puberty starting much later.”可知，对MC3R的进一步研究将有助于找出应对儿童发育迟缓问题的新方法。
15. D 词义猜测题。根据第四段第二句可知，MC3R功能正常时，会发信号让身体快速成长。再根据画线词所在句中的“help redirect...with the prospect of improving the physical functionality of such patients”可推知，未来的研究将针对是否能用药物“激活”MC3R，从而帮助改善肌肉以及其他组织的功能。因此，stimulate“刺激；激发”与画线词意思相近。