備考下半年的公共英語三級考試要求考生做好閱讀的準備。下面，小編為大家送上一篇公共英語三級閱讀文章，歡迎閱讀。
Plankton
Scattered through the seas of the world are billions of tons of small plants and animals called plankton. Most of these plants and animals are too small for the human eye to see. They drift about lazily with the currents, providing a basic food for many larger animals.
Plankton has been described as the equivalent of the grasses that grow on the dry land continents, and the comparison is an appropriate one. In potential food value, however, plankton far outweighs that of the land grasses. One scientist has estimated that while grasses of the world produce about 49 billion tons of valuable carbohydrates each year, the sea's plankton generates more than twice as much.
Despite its enormous food potential, little effect was made until recently to farm plankton as we farm grasses on land. Now marine scientists have at last begun to study this possibility, especially as the sea's resources loom even more important as a means of feeding an expanding world population.
No one yet has seriously suggested that "planktonburgers" may soon become popular around the world. As a possible farmed supplementary food source, however, plankton is gaining considerable interest among marine scientists.
One type of plankton that seems to have great harvest possibilities is a tiny shrimplike creature called krill. Growing to two or three inches long, krill provide the major food for the great blue whale, the largest animal ever inhabit the Earth. Realizing that this whale may grow to100 feet and weigh 150 tons at maturity, it is not surprising that each one devours more than one ton of krill daily.
浮游生物
數十億噸的被稱為"浮游生物"的小動物、植物散佈在世界的海洋中。這些小的動、植物大多太小而難以被人眼看到。它們隨波逐流，為許多較大的動物提供了基本的食物。
浮游生物曾被描述為生長在大陸陸地上的各種草類的海洋對應物。 這種比喻是恰當的。然而就潛在的食物價值而言，浮游生物遠勝於草類。一位科學家曾經估計，世界上的'草類每年生產大約 490 億噸有用的碳水化合物，而海洋裡的浮游生物每年生產的碳水化合物多於此數的兩倍。
儘管浮游生物具備巨大的食物潛能，但直到最近人們還很少象種植草類那樣付出努力養殖浮游生物。現在，海洋科學家們至少已開始研究這種可能性。全球人口不斷擴張，海洋資源作為食品的重要性日益突出。
現在還沒有人認真說過"浮游生物漢堡" 會很快在世界上流行起來。然而，作為一種可能養殖的補充性食物資源，浮游生物正引起了海洋科學家們相當大的興趣。
一種似乎具有很大收穫可能性的微小的蝦狀浮游生物被稱為鱗蝦。鱗蝦長至 2～3 英寸長時即成為地球上曾居住過的最大動物——藍鯨的主要食物。成熟的藍鯨可以達到 100 英尺長，150 噸重，所以每頭鯨每天吞食 1 噸多的鱗蝦一點也不讓人吃驚。
附：公共英語三級閱讀技巧之如何做原因性的題目
由於閱讀理解的文章絕大多數是屬於說明文體裁，而說明文的主要功能是對事物、現象的解釋和闡述。因此許多題目都涉及到分析和辨別事物的原因或成因。例如：
The main reason for the failure of the organization to achieve the success is that _____.
Mouthwashes are not effective cure for bad breath mainly BECause _________.
Which of the following is mentioned as one of the causes for the earthquake ______.
在做尋找事物原因的題目時，有幾點要特別注意。
1.問的是主要原因或真正原因，而命題人員總把一些次要的，非直接的，非根本的原因放進選項。由於這些次要的原因也是文章中提到的，因此考生如不仔細，往往會把次要原因當作答案。
這就告訴我們，做這類題目，首先要注意問題中的the main/chief/real cause (reason，factor) 這些詞，提醒自己，問題問的是主要原因。然後分析事物的諸多的原因，理出最主要的，直接的，根本的原因。
2.問的是事物的原因，但出現在選項裡的還有事物的後果、影響。由子這些後果、影響和原因一樣，都是指一件事，且都出現在同一相關段，或相關句中，稍不留心，就會搞錯。
這就告訴我們，做尋找原因的題目時，對文章所說的事物的原因、結果、影響，應理清它們之間的邏輯關係。不要錯把結果當原因。
