關(guān)于英語(yǔ)的節(jié)選文摘
英語(yǔ)作文的提升其實(shí)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(yǔ)的文摘，只要我們認(rèn)真的學(xué)習(xí)這樣才可以快速的提高成績(jī)，有需要的同學(xué)可以收藏起來(lái)哦，大家快點(diǎn)學(xué)習(xí)起來(lái)哦
為什么人類(lèi)身上沒(méi)有斑點(diǎn)或條紋?
Why Don’t Humans Have Spots Or Stripes?
為什么人類(lèi)身上沒(méi)有斑點(diǎn)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(jīng)好奇過(guò)為什么我們?nèi)祟?lèi)身上沒(méi)有斑點(diǎn)或條紋?也許你沒(méi)想過(guò)，可那么多生物五彩斑斕，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(lèi)和動(dòng)物的皮膚顏色來(lái)自黑色素，它不是黑色就是黃色。二者混合可呈現(xiàn)你能見(jiàn)到的各種哺乳動(dòng)物的皮膚顏色：白色、黃色、棕色、黑色和他們之間的過(guò)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(chǎn)生黑色素的皮膚細(xì)胞是黑素細(xì)胞，在哺乳動(dòng)物的胚胎中，黑素細(xì)胞源自制造出脊髓和大腦的同組細(xì)胞。這些細(xì)胞從那里出來(lái)通過(guò)皮膚的生長(zhǎng)遷往動(dòng)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(chǎn)生深淺色素的黑素細(xì)胞以條紋狀遷移，那么你身上就有條紋。斑點(diǎn)也是這么來(lái)的。但在這種情況下， 只有隨機(jī)的某些色素斑點(diǎn)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(duì)于特定物種 ，比如斑馬， 條紋因可作為偽裝對(duì)進(jìn)化有利。身上有條紋的動(dòng)物更有可能生存下來(lái)，并把能產(chǎn)生條紋的基因傳給后代。對(duì)于人類(lèi)來(lái)說(shuō)，情況顯然不同。但是我們?nèi)砥つw的顏色也可能是適應(yīng)環(huán)境的結(jié)果。
亞硫酸鹽是什么?
What Are Sulfites?
亞硫酸鹽是什么?
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(shè)想一下，你在晚餐時(shí)剛剛打開(kāi)了一瓶酒，你會(huì)在酒瓶的標(biāo)簽上看到：含亞硫酸鹽。亞硫酸鹽是什么?這些成分在你的酒中發(fā)揮什么樣的作用呢?
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(jiàn)的一種化合物。幾千年前，人們就發(fā)現(xiàn)了亞硫酸鹽的一些妙用：它們能殺死細(xì)菌，或者降低細(xì)菌滋生和發(fā)酵的速度。這個(gè)發(fā)現(xiàn)對(duì)于釀酒師來(lái)說(shuō)是非常重要的，他們通常會(huì)在酒中加一些特定的酵母使酒發(fā)酵，但是同時(shí)，他們又不想野生酵母和細(xì)菌破壞了這個(gè)過(guò)程。而亞硫酸鹽就能阻止酒的腐壞，在其中發(fā)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(fā)酵過(guò)程中數(shù)量會(huì)有稍許的增加。但是，為了有效利用亞硫酸鹽的防腐作用，釀酒師們通常會(huì)在釀酒過(guò)程中多添加一點(diǎn)點(diǎn)亞硫酸鹽。埃及人也曾使用亞硫酸鹽對(duì)酒類(lèi)容器進(jìn)行殺菌，而且，亞硫酸鹽被添加進(jìn)入酒類(lèi)也已經(jīng)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(guān)系其實(shí)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(lèi)有添加亞硫酸鹽，需要在標(biāo)簽上注明，為什么?
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?yàn)橛醒芯咳藛T之前發(fā)現(xiàn)，有不到1%的人會(huì)對(duì)亞硫酸鹽產(chǎn)生過(guò)敏反應(yīng)，雖然多數(shù)人的反應(yīng)比較輕微，比如說(shuō)會(huì)起很癢的皮疹，但有部分人的過(guò)敏反應(yīng)會(huì)威脅到生命安全，這些反應(yīng)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(jīng)常會(huì)在哮喘癥患者身上看到這些少有但嚴(yán)重的反應(yīng)。其實(shí)，也并不是所有的哮喘癥患者都會(huì)對(duì)亞硫酸鹽過(guò)敏，標(biāo)簽上的說(shuō)明只是為了警示需要注意的人避開(kāi)這些成分。就像老話(huà)常說(shuō)的那樣，酒后，現(xiàn)在是標(biāo)注在標(biāo)簽上-吐真言!
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