【题目】 The other day, I bought an expensive anti-aging cream that promised to make my face look several years younger that other women by fighting free radicals. It made me curious about what free radicals ares.Is the anti-aging cream the only way I need to protect myself?
“As a scientific term, free radicals are essentially unstable atoms, “says Arizona-based doctor, Natasha Bhuyan, M. D. “In medicine, they cause cells to break down over time and are linked to aging.”
A super simple chemistry review for you: Atoms from different elements are the building blocks that make up water, nitrogen and more. Electrons (电子) are the negatively charged atoms, and they like to be in pairs. When an electron loses its partner, it creates a free radical, which is usually unstable and highly reactive. Free radicals typically go through the body to seek out a replacement for their missing electron, and that can result in damage to cells,proteins and DNA.
So how do free radicals form and why do they happen? Bhuyan says, “Scientifically, free radicals are unpaired electrons that are seeking a mate to bond with. The theory behind free radicals is that they can lead to the imbalance between free radicals and antioxidants (抗氧化剂).” Another mini-science lesson for you: Antioxidants are natural or man made matters that can help delay or prevent some types of cell damage. They’re often found in fruits and vegetables.
A lot of the aspects of modern life — our diet, lifestyle and environmental factors like pollution, can cause oxidative stress. Over time, oxidative stress weakens cell and tissues and can leave you more easily to certain health issues including cancer. And, as beauty marketers are keenly aware,oxidative stress can also speed up the aging process. Now that your know free radicals can weak on your health, you’re probably wondering if there are any ways to prevent them from forming or at least to minimize their negative effects.
【1】What does the author intend to do in paragraph 1?
A.Explain the process of aging.B.State the formation of free radicals.
C.Introduce the topic of free radicals.D.Describe the harm of anti aging cream.
【2】Which of the following do free radicals refer to?
A.Unpaired electrons.B.Steady atoms.
C.Replacements of atoms.D.Functions of electrons.
【3】What can we learn about antioxidants from the text?
A.They have never been found in nature.
B.They do harm to cells, proteins and DNA.
C.They can slow down the damage of some cells.
D.They always keep balance with free radical.
【4】What will the author probably tell us next?
A.What exactly oxidative stress is.B.How beauty marketers promote sales.
C.Where a variety of diseases come from.D.Whether free radicals can be prevented.
【答案】
【1】C
【2】A
【3】C
【4】D
【解析】
这是一篇说明文。文章主要介绍了自由基是怎样形成的和自由基是怎样影响人的身体的。
【1】推理判断题。根据第一段The other day, I bought an expensive anti-aging cream that promised to make my face look several years younger that other women by fighting free radicals. It made me curious about what free radicals ares. Is the anti-aging cream the only way I need to protect myself?可知，前几天，我买了一款昂贵的抗衰老面霜，据说它能对抗自由基，让我的脸看起来比其他女性年轻好几岁。这让我好奇什么是自由基。抗衰老面霜是我唯一需要保护自己的方法吗？由此可推知，作者第一段讲述了她买了一个抗衰老的面霜来抵抗自由基给脸部留下岁月的痕迹的事，从而引出自由基的话题。故选C。
【2】细节理解题。根据第三段中Electrons (电子) are the negatively charged atoms, and they like to be in pairs.可知，电子是带负电荷的原子，它们喜欢成对出现。以及第四段中Bhuyan says, “Scientifically, free radicals are unpaired electrons that are seeking a mate to bond with.可知Bhuyan说：“从科学上讲，自由基是寻找配偶的未配对电子。”由此可知，自由基指的是不成对的电子。故选A。
【3】细节理解题。根据第四段中Another mini-science lesson for you: Antioxidants are natural or man made matters that can help delay or prevent some types of cell damage.可知，另一个小科学课：抗氧化剂是天然或人造物质，可以帮助延缓或防止某些类型的细胞损伤。由此可知，抗氧化剂可以减缓一些细胞的损伤。故选C。
【4】推理判断题。根据最后一段中Now that your know free radicals can weak on your health, you’re probably wondering if there are any ways to prevent them from forming or at least to minimize their negative effects.可知，既然你知道了自由基会损害你的健康，你可能想知道是否有办法阻止它们的形成，或者至少把它们的负面影响降到最低。由此可推知，作者接下来可能会围绕“自由基的形成是否能被阻止”展开。故选D。
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Take time to chew your food and enjoy mealtimes. 【2】 We tend to rush through our meals, forgetting to enjoy the flavor and feel the taste of what is in our mouths.
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