英語聽力文摘 藻類生物燃料
作為不依賴于化石資源的燃料，生物燃料逐漸得到普遍認(rèn)可。但在應(yīng)用上，使用高等植物的現(xiàn)有手段還存在極限。其原因在于單位面積的收獲量較小，并且還會浪費珍貴的水資源。作為解決之策，業(yè)界開始開發(fā)使用藻類的生物燃料。這樣的話，不僅單位面積的收獲量可達(dá)到現(xiàn)有手段的3～40倍，而且基本上不用水。不過，要想實用化，今后還必須要降低成本，不斷摸索與吸收CO2相結(jié)合的方法。
If you’re like many people, when you think of algae you picture the unsightly green film that forms on neglected swimming pools and fish tanks.
Scientists, however, have made some discoveries that might change the way you think about this common plant.
Researchers are working on ways to use algae to reduce our dependence on fossil fuels to power cars, trucks, and even airplanes. Algae has attracted attention because it is simple and economical to grow and carries fewer financial and environmental costs when compared to other alternatives.
Algae needs only water to grow, and can use fresh water, salt water, marshlands, and even wastewater for a habitat. The plant’s highly-adapted photosynthesis process allows it to thrive anywhere that abundant sunshine can be found. And even sunshine is optional for this versatile plant because scientists have discovered ways to grow algae in the dark using sugar as a food source.
To use algae as a replacement for fossil fuels, oil is extracted from the plant and developed into a biofuel that can be burned in diesel engines. The yield produced from the algae has proven far greater than other biofuels currently being developed. For example, soy produces an average yield of fifty gallons of biofuel per acre per year. Canola, another common alternative, produces roughly 130 gallons of biofuel per acre per year. In contrast, scientists have found that algae can produce up to 4,000 gallons of biofuel per acre per year.
In addition, because algae can be grown on water rather than land and without fertilizers, it may prove to be a more efficient and (1)environmentally sound alternative to the biofuels in use today. In the future, then, when you see algae you might think about more than just pond scum!
譯文：
如許多人一樣 ，當(dāng)你想到藻類的時候，你會在腦海中即刻閃現(xiàn)出在無人問津的游泳池和魚池里表面覆蓋著一層難看的綠膜的畫面。
然而科學(xué)家的發(fā)現(xiàn)卻可以改變你對這種普通植物的看法。
研究人員正致力于如何利用藻類來減少我們對用化石燃料發(fā)動小車，卡車甚至飛機(jī)的依賴。藻類會引起科學(xué)家們的注意是因為相對于其它可選擇的燃料來說，種植藻類更簡單，經(jīng)濟(jì)，并且花費的財政和環(huán)境成本較少。
只要有水藻類就可以存活，它可以在淡水，咸水，沼澤地，甚至污水中生長。該植物高度適應(yīng)的光合作用過程讓其在任何陽光充足的地方都能茁壯成長。甚是陽光也只是一個可選擇的條件，因為科學(xué)家們發(fā)現(xiàn)通過把糖作為食物來源也可以在黑暗中種植藻類。
若用藻類代替化石燃料，油就會從植物中提取出來，并被加工為可以在柴油機(jī)中燃燒的生物燃料。藻類的產(chǎn)量大大高于目前正在開發(fā)的其他生物燃料。例如，大豆平均每年每英畝可生產(chǎn)五十加侖的生物燃料。菜籽，另一種常見的替代品，平均每年每英畝大約可生產(chǎn)130加侖。與此相反，科學(xué)家們發(fā)現(xiàn)藻類平均每年每英畝可生產(chǎn)達(dá)4000加侖。
此外，藻類可以在水中而不是陸地上生長，也不需要施肥。因此可以證明目前在使用的生物燃料中它是更有效更環(huán)保的替代品。未來，當(dāng)你看到藻類的時候你或許想到的不僅僅是“池塘敗類”。
Notes:
(1)environmentally sound對環(huán)境無害的
Voluntary offset programs, however, are not regulated, so consumers cannot be sure that they are investing in environmentally sound projects.
然而，志愿性的抵消計畫并未受到管理，因此消費者無法確定他們投資的是保護(hù)環(huán)境的計畫。
