字神帝國英語天地

Merry Xmas 同學們~~

今日主題：Bahamas Creation Linked to African Dust
巴哈馬群島的形成和非洲灰塵有關

洪欣老師推薦：托福聽力最好的課外教材：60-Second Science
康康精選托福會考的主題，堅持每天精聽一定會進步的哦!!

建議方法：
1. 先聽兩三遍 (不看文稿)
2. 再一句一句聽寫 (每句都要聽寫數遍，直到寫出85%以上的字)
3. 最後check文稿，看哪聽不出來，單字沒背過，還是發音不熟。
4. 堅持天天聽，就能每天進步哦。

MP3音檔 (按右鍵可下載聽)：喜歡的同學，幫忙推或按讚哦~~
http://online1.tingclass.net/voas…/2014/20140811sa_earth.mp3

只有音檔怎夠，聽不懂地方，不用怕，康康幫你準備好中英文稿了：

中英文稿：
Imagine paradise. Now imagine the Bahamas. Hard to tell the difference. The island nation boasts brilliant white sands, clear waters and vibrant coral reefs.
這裡是想像的天堂。現在想像一下巴哈馬群島。你很難講出它的獨特之處。這個島國擁有亮白的沙灘，清澈的海水和充滿生氣的珊瑚礁。

The waters of the Bahamas are so clear because they're low in nutrients. They're therefore relatively free of the microscopic life that turns richer waters murky—and is normally associated with the deposition of calcium carbonate. So how did the reefs come to be?
巴哈馬的海水是如此清澈是因為營養鹽含量低。因此它們相對的擺脫了微生物的影響，這些微生物可以使得營養較豐富的海水變得朦朧，這通常和碳酸鈣沉澱物有關。所以礁石是怎樣形成的呢?

A group of scientists argue that dust from across the Atlantic in Africa may have initiated the process.
一組科學家認為可能是非洲的灰塵橫跨大西洋來到這裡，從而開始了這一進程。

Dust blows off the Sahara today, reaching all the way to the Americas. Fertilized by the dust, cyanobacteria can then grow and pull carbon dioxide out of the water. That activity in turn causes calcium carbonate to precipitate, an event known as a whiting. And the cyanobacteria also fix nitrogen from the atmosphere, helping other microorganisms to thrive. You can find more 60-Second Earth on chinavoa.com.
灰塵從現在的撒哈拉沙漠被吹起來，一直到達了美洲。藍藻細菌經過這些灰塵的受精，就可以生長，並把水中的二氧化碳排放出水面。這個過程反過來也了導致碳酸鈣沉澱的形成，該過程又叫做whiting反應。而且藍藻細菌也可以調整空氣中的氮含量，幫助其他微生物茁壯成長。

This may have been going on for a very long time. Enough of such cyanobacterial work over enough time and eventually you get the Bahamas, built out of calcium carbonate. At least that's what's suggested by trace elements in Bahama sediments. The hypothesis is in the journal Geology. [P. K. Swart et al, The fertilization of the Bahamas by Saharan dust: A trigger for carbonate precipitation?]
這個過程可能需要很長一段時間，需要足夠多的這種藍藻細菌，在足夠多的時間裡共同努力，最終才會得到這個用碳酸鈣建造起來的巴哈馬群島。至少這是通過查探巴哈馬群島的沉澱物之後而提出的。該假設被發表在《地質學》雜誌上。

Fertilizing similarly nutrient poor waters might help reduce rising levels of carbon dioxide that are causing uncomfortable global warming. And maybe we'd get some pretty nice islands out of the deal—eventually.—David Biello
類似的，施肥少的水域可能會有助於減少一直在不斷上漲的二氧化碳濃度，二氧化碳過多會我們感覺不舒服，還會導致全球變暖。或許最終，我們可以利用這種方法得到一些非常美麗的島嶼。—戴維‧別洛