雅思阅读第098套P1-An Essential Intermediary

Reading Passage One

You should spend about 20minutes on Questions 1-13, which are based on Reading Passage One.

An Essential Intermediary

There is a strange irony aboutthe blue whale. With fully grown adults reaching up to 30 metres long, andweighing in at almost 200 tons, it is not only the largest animal in the world,but also the largest to have ever existed. Yes, not even the most imposing ofthe dinosaurs from the Jurassic era can match this sleek streamlined aquaticmammal in scale. So, where is the irony? It lies in the fact that this hugebeast feeds primarily on one of the smallest life forms in the oceans, a tinycrustacean known as krill.

Krill live in every ocean ofthe world. They thus come in many varieties, although all sporting a similarshrimp-like appearance, with an exoskeleton divided into three parts, and withtwo large antennae at the front, and pairs of legs running down the underside.These creatures are distinguishable from shrimp by their gills, which areexternally mounted, and resemble rows of fibrous combs alongside their bodies.Another oddity is that their exoskeleton is usually transparent. This, andtheir small size, lead to the deceptive conclusion that they are an insubstantialpresence, of little importance, until one is informed that an adult blue whalecan consume almost 40 million krill, with a total weight of 3,600 kilograms, injust one day.

It is this, their huge numbers,which makes these mysterious ghost-like crustaceans so important. Just lookingat one species, the Antarctic krill, their collective weight (or bio-mass) isestimated to be about 500 million tons. Putting this another way, that is overtwice the weight of all human beings currently on Earth. Some scientistsestimate that, each year, as much as half of this is eaten by whales, seals,penguins, squid, and fish, illustrating that krill constitute an enormous foodresource for other animals. The question is whether humans can get in on theact.

Antarctic krill are the largestspecies, at six centimeters. Most other species are about two centimeters, andthis makes them awkward to catch. Very fine fishing nets are needed, but theseare difficult to drag through the water, quickly clogged, and easily broken. Inaddition, when lifted in large piles, the delicate krill crush each other,forcing out their internal fluids. They must also be peeled due to thedangerously high levels of fluoride in their exoskeleton, and finally, theymust be quickly prepared and frozen due to the strong enzymes in their gut,which would otherwise cause rapid putrefaction. It is problems such as thesewhich have limited processed krill to being mostly used as fish food inaquariums or aquaculture, or bait in commercial fishing operations, butotherwise very much out of the public’s mind.

Seafood-loving Japan is theonly country in the world in which some krill end up on the table. The boiled,peeled, then frozen tail-meat is sold on the market, and there is somelower-grade krill-paste used as a food flavouring or colouring agent. Theseproducts originate from the small North-Pacific krill, yet it is the largeAntarctic species which would seem to offer the best commercial prospects, andperhaps a more appetising meal. The majority of krill trawlers thus target thewaters around coastal Antarctica, but it is a remote region, subject to harshweather conditions, making operations there difficult and expensive, as well asraising issues of the ecological consequences, especially given the importanceof krill as the basis of the food chain in that pristine and untouchedenvironment.

Yet to explore this food chainfully, one must go smaller still. Krill themselves are filter feeders, usingvery fine comb-like appendages on the front of their bodies to extractmicroscopic organisms known as phytoplankton. These live in almost every bodyof water in the world, but only in the well-lit surface layers, since theseorganisms need exposure to sunlight, from which they obtain their energy. Inthe same way that plants on land are ultimately the basis of all food chainsthere, so too are phytoplankton in the oceans. Since krill exist in such largenumbers, logically then, their primary food source must be even more numerous.There is, in fact, so much phytoplankton that their collective photosynthesisaccounts for up to half of the oxygen produced in the world.

However, as with krill, thevast numbers of phytoplankton live unnoticed and unobserved. Their presence canonly be indirectly deduced when they are pressed together by currents, wherethere can be correspondingly high concentrations of krill feeding on them. Thiscan similarly result in the usually solitary blue whales being found together,and revealing one of the most remarkable and elusive food chains in nature:from phytoplankton, to krill, to the blue whale. In other words, from thetiniest elements in nature, in two short steps leading to a mighty andawe-inspiring leviathan of the deep, the largest animal that has ever existed.And the small ghostly krill are the essential intermediary in this wondrousprocess.

SECTION 1: QUESTIONS 1-13

Questions 1-4

Do the following statementsagree with the information given in Reading Passage One?

Write

TRUE

if the statement agrees with the information

FALSE

if the statement contradicts the information

NOT GIVEN

If there is no information on this

1 _________________    Some dinosaurs were bigger than the blue whale.

2 _________________    The blue whale does not only eat krill.

3 _________________    Some krill are smaller than shrimp.

4 _________________    There are about 500 million tons of krill inthe ocean.

Questions 5-9

Complete the diagram.

Choose ONE WORD from thepassage for each answer.

5 _________________

6 _________________

7 _________________

8 _________________

9 _________________

Questions 10-13

Choose the correct letter, A,B, C, or D.

10Fishing for krill is

Anot too difficult.

Bmostly done in Antarctic waters.

Cmostly done in Japanese waters.

Ddone with large fishing nets.

11Krill

Amove like ghosts.

Bare processed soon after capture.

Care mostly used for human consumption.

Dcome in two varieties.

12Phytoplankton

Aoutnumber krill.

Bproduce over half of the oxygen in theworld.

Ccan be seen with the naked eye.

Dcan live anywhere in the ocean.

13Blue whales

Aare a very large species offish.

Bcan weigh 200 tons.

Cprefer to be alone.

Dare in the middle of a food chain.

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答案

雅思阅读第098套P1-An Essential Intermediary

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雅思阅读第098套P1:An Essential Intermediary