關於英語的節選文摘

英語作文的提升其實是很容易的，但是大家一定不可以偷懶哦小編今天給大家整理了英語的文摘，只要我們認真的學習這樣纔可以快速的提高成績，有需要的同學可以收藏起來哦，大家快點學習起來哦

　　爲什麼人類身上沒有斑點或條紋?

Why Don’t Humans Have Spots Or Stripes?

爲什麼人類身上沒有斑點或條紋?

Have you ever wondered why we humans don’t have spots or stripes? Well, maybe you haven’t, but it is interesting that so many creatures are multicolored but we are not.

你是否曾經好奇過爲什麼我們人類身上沒有斑點或條紋?也許你沒想過，可那麼多生物五彩斑斕，我們卻不是，這很有意思。

Melanin Pigments

黑色素

Humans and animals get their skin color from melanin pigments, which can be either black or yellow. Together, these two pigments account for just about every color you might see on the skin of mammals: white, red, yellow, brown, and black and every shade in between.

人類和動物的皮膚顏色來自黑色素，它不是黑色就是黃色。二者混合可呈現你能見到的各種哺乳動物的皮膚顏色：白色、黃色、棕色、黑色和他們之間的過渡色。

The skin cells that produce melanin are known as melanocytes. In the embryos of mammals, the melanocytes originate from the same group of cells that produces the spinal cord and the brain. From there, these cells migrate through the developing skin towards the belly of the animal.

產生黑色素的皮膚細胞是黑素細胞，在哺乳動物的胚胎中，黑素細胞源自制造出脊髓和大腦的同組細胞。這些細胞從那裏出來通過皮膚的生長遷往動物的肚子。

Streaks and Stripes

條紋和條痕

If the melanocytes that produce dark pigments and light pigments migrate in streaks, you end up with stripes. The same goes for spots, but in this case, only random patches of certain pigments survive. In either case, the migration pattern is genetically determined.

如果產生深淺色素的黑素細胞以條紋狀遷移，那麼你身上就有條紋。斑點也是這麼來的。但在這種情況下， 只有隨機的某些色素斑點能夠存活。不論哪種情況，其遷移方式由基因決定。

For certain species, like zebras, stripes provided an evolutionary advantage because they worked as camouflage. Those animals with stripes were more likely to survive, and to pass along the genes that produce stripes to their offspring. For humans, this apparently wasn’t the case. However, it’s likely that our overall skin color probably is a result of adaptation as well.

對於特定物種 ，比如斑馬， 條紋因可作爲僞裝對進化有利。身上有條紋的動物更有可能生存下來，並把能產生條紋的基因傳給後代。對於人類來說，情況顯然不同。但是我們全身皮膚的顏色也可能是適應環境的結果。

　　亞硫酸鹽是什麼?

What Are Sulfites?

亞硫酸鹽是什麼?

You’ve just opened a bottle of wine for dinner. On the label, you see these words: Contains Sulfites. What are sulfites? And what are they doing in your wine?

設想一下，你在晚餐時剛剛打開了一瓶酒，你會在酒瓶的標籤上看到：含亞硫酸鹽。亞硫酸鹽是什麼?這些成分在你的酒中發揮什麼樣的作用呢?

Chemical Compounds

化合物

Sulfites are chemical compounds found naturally in grapes, garlic and other plants. Thousands of years ago, people realized something nifty about sulfites: they kill or slow the growth of bacteria and most yeasts. This comes in handy for winemakers, who add specific yeasts to ferment wine, and don’t want wild yeasts or bacteria to spoil it. Sulfites prevent spoilage in wine, acting as a preservative.

亞硫酸鹽是在葡萄，大蒜和其他植物中常見的一種化合物。幾千年前，人們就發現了亞硫酸鹽的一些妙用：它們能殺死細菌，或者降低細菌滋生和發酵的速度。這個發現對於釀酒師來說是非常重要的，他們通常會在酒中加一些特定的酵母使酒發酵，但是同時，他們又不想野生酵母和細菌破壞了這個過程。而亞硫酸鹽就能阻止酒的腐壞，在其中發揮了防腐劑的作用。

The amount of sulfites naturally in grapes is very small, and there’s a bit more produced during fermentation. But to take full advantage of sulfites’ preservative abilities, winemakers add a little more to the process. The Egyptians sterilized wine containers with sulfites, and sulfites have been added to wine for hundreds of years.

葡萄中含有亞硫酸鹽的量非常少，在發酵過程中數量會有稍許的增加。但是，爲了有效利用亞硫酸鹽的防腐作用，釀酒師們通常會在釀酒過程中多添加一點點亞硫酸鹽。埃及人也曾使用亞硫酸鹽對酒類容器進行殺菌，而且，亞硫酸鹽被添加進入酒類也已經有了幾百年歷史了。

Wine And Sulfites

酒和亞硫酸鹽

So the relationship between wine and sulfites goes way back. But in 1985, the Food and Drug Administration required wine with added sulfites to say so on the label. Why?

因此，酒和亞硫酸鹽的關係其實可以回溯到很久很久以前。但在1985年，食品與藥品管理局要求，若酒類有添加亞硫酸鹽，需要在標籤上註明，爲什麼?

Researchers had recently discovered that less than one percent of the population is sensitive to sulfites. Most have mild reactions, like an itchy rash. But some folks have life-threatening reactions, including difficulty breathing and low blood pressure.

因爲有研究人員之前發現，有不到1%的人會對亞硫酸鹽產生過敏反應，雖然多數人的反應比較輕微，比如說會起很癢的皮疹，但有部分人的過敏反應會威脅到生命安全，這些反應包括呼吸困難或低血壓等。

These rare but serious reactions are most often seen in asthmatics. Not all asthmatics are sensitive to sulfites, but the label’s there for those who need to steer clear. As the old saying goes, in wine–and now on the label–there is truth!

我們經常會在哮喘症患者身上看到這些少有但嚴重的反應。其實，也並不是所有的哮喘症患者都會對亞硫酸鹽過敏，標籤上的說明只是爲了警示需要注意的人避開這些成分。就像老話常說的那樣，酒後，現在是標註在標籤上-吐真言!