【題目】 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 (電子) 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 (抗氧化劑).” 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】

這是一篇說明文。文章主要介紹了自由基是怎樣形成的和自由基是怎樣影響人的身體的。

【1】推理判斷題。根據(jù)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，前幾天，我買了一款昂貴的抗衰老面霜，據(jù)說它能對抗自由基，讓我的臉看起來比其他女性年輕好幾歲。這讓我好奇什么是自由基。抗衰老面霜是我唯一需要保護自己的方法嗎？由此可推知，作者第一段講述了她買了一個抗衰老的面霜來抵抗自由基給臉部留下歲月的痕跡的事，從而引出自由基的話題。故選C。

【2】細節(jié)理解題。根據(jù)第三段中Electrons (電子) are the negatively charged atoms, and they like to be in pairs.可知，電子是帶負電荷的原子，它們喜歡成對出現(xiàn)。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說：“從科學上講，自由基是尋找配偶的未配對電子�！庇纱丝芍杂苫傅氖遣怀蓪Φ碾娮�。故選A。

【3】細節(jié)理解題。根據(jù)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，另一個小科學課：抗氧化劑是天然或人造物質(zhì)，可以幫助延緩或防止某些類型的細胞損傷。由此可知，抗氧化劑可以減緩一些細胞的損傷。故選C。

【4】推理判斷題。根據(jù)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會損害你的健康，你可能想知道是否有辦法阻止它們的形成，或者至少把它們的負面影響降到最低。由此可推知，作者接下來可能會圍繞“自由基的形成是否能被阻止”展開。故選D。

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