托福阅读tpo45R-3原文+译文+题目+答案+背景知识

tpo45阅读-3Feeding Strategies In The Ocean
原文 (1)
译文 (2)
题目 (3)
答案 (8)
背景知识 (8)
原文
Feeding Strategies In The Ocean
①In the open sea, animals can often find food reliably available in particular regions or seasons (e g., in coastal areas in springtime). In these circumstances, animals are neither constrained to get the last calorie out of their diet nor is energy conservation a high priority. In contrast, the food levels in the deeper layers of the ocean are greatly reduced, and the energy constraints on the animals are much more severe . To survive at those levels, animals must maximize their energy input, finding and eating whatever potential food source may be present.
②In the near-surface layers, there are many large, fast carnivores as well as an immense variety of planktonic animals, which feed on plankton (small, free-floating plants or animals) by filtering them from currents of water that pass through a specialized anatomical structure. These filter-feeders thrive in the well-illuminated surface waters because oceans have so many very small organisms, from bacteria to large algae to larval crustaceans. Even fishes can become successful filter-feeders in some circumstances. Although the vast majority of marine fishes are carnivores, in near-surface regions of high productivity the concentrations of larger phytoplankton (the plant component of plankton) are sufficient to support huge populations of filter-feeding sardines and anchovies. These small fishes use their gill filaments to strain out the algae that dominate such areas. Sardines and anchovies provide the basis for huge commercial fisheries as well as a food resource for large numbers of local carnivores, particularly seabirds. At a much larger scale, baleen whales and whale sharks are also efficient filter-feeders in productive coastal or polar waters, although their filtered particles comprise small animals such as copepods and krill rather than phytoplankton.
③Filtering seawater for its particulate nutritional content can be an energetically demanding method of feeding, particularly when the current of water to be filtered has to be generated by the organism itself, as is the case for all planktonic animals. Particulate organic matter of at least 2.5 micrograms per cubic liter is required to provide a filter-feeding planktonic organism with a net energy gain.
This value is easily exceeded in most coastal waters, but in the deep sea, the levels of organic matter range from next to nothing to around 7 micrograms per cubic liter. Even though mean levels may mask much higher local concentrations, it is still the case that many deep-sea animals are exposed to conditions in which a normal filter-feeder would starve.
④There are, therefore, fewer successful filter-feeders in deep water, and some of those that are there have larger filtering systems to cope with the scarcity of particles. Another solution for such animals is to forage in particular layers of water where the particles may be more concentrated. Many of the groups of animals that typify the filter-feeding lifestyle in shallow water have deep-sea representatives that have become predatory. Their filtering systems, which reach such a high degree of development in shallow- water species, are greatly reduced. Alternative methods of active or passive prey capture have been evolved, including trapping and seizing prey, entangling prey, and sticky tentacles.
⑤In the deeper waters of the oceans, there is a much greater tendency for animals to await the arrival of food particles or prey rather than to search them out actively (thus minimizing energy expenditure). This has resulted in a more stealthy style of feeding, with the consequent emphasis on lures and/or the evolution of elongated appendages that increase the active volume of water controlled or monitored by the animal. Another consequence of the limited availability of prey is that many animals have developed ways of coping with much larger food particles, relative to their own body size, than the equivalent shallower species can process. Among the fishes there is a tendency for the teeth and jaws to become appreciably enlarged. In such creatures, not only are the teeth hugely enlarged and/or the jaws elongated but the size of the mouth opening may be greatly increased by making the jaw articulations so flexible that they can be effectively dislocated. Very large or long teeth provide almost no room for cutting the prey into a convenient size for swallowing, the fish must gulp the prey down whole.
译文
海洋中的捕食策略
①在开阔的海域，动物们经常能在特定的区域或季节找到稳定的食物来源（比如在春天的沿海地区）。

在这种情况下，动物们既不用完全将食物中的热量消化吸收，也不必将保存能量视为最重要的事。

然而，海洋深处的食物数量会大大减少，因此这对动物能量约束会更严重。

要在这个深度的海域生存，动物们必须最大化摄入能量，去寻找和食用任何存在的潜在食物来源。

②在接近表层的地方，有很多大型的，移动速度很快的食肉动物，还有大量的浮游动物以浮游生物为食（微小能够自由漂浮的植物和动物），浮游动物通过一种特殊的结构穿过水流。

这些滤食动物在有亮光的海水表层繁殖，因为海洋中有太多微小生物，从细菌到大的海藻，还有甲壳类幼虫。

即使在有些情况下，鱼也可以变为成功的滤食动物。

尽管大多数海洋中的鱼是食肉动物，但在接近表层的区域，大量的浮游植物（浮游生物的植物成分）足够支撑大量的沙丁鱼和凤尾鱼等滤食动物。

这些小鱼会用它们的鳃丝过滤这个区域主要的藻类。

沙丁鱼和凤尾鱼是大量渔业的基础，同时也是大量当地食肉动物的食物来源，尤其是海鸟的食物。

体型更大的须鲸和鲸鲨在多产的海岸和极地水域也是高效滤食动物，尽管它们的过滤对象是小动物（比如桡足动物和磷虾），而不是浮游生物。

③过滤海水去汲取微小的营养成分是一种高能量需求的摄取营养方式，尤其是当过滤水流必须要由生物自己来完成，正如所有浮游动物所做的一样。

每立升海水必须含有2.5毫克微小有机物，才能保证滤食动物的净能量摄入。

在大多数沿海区域都能轻松超过这个数值，但在深海区域，有机物含量每立升从几乎没有到大概7毫克都有。

即使在深海有机物含量低可能忽略了部分高浓度区域的存在，但很多深海动物都是处于一个恶劣的状况，也就是正常的滤食动物会饿死的情况。

④因此，深海中少有成功的滤食动物，其中一些有大的过滤系统来对抗生物的稀缺。

这些动物还有另一个解决办法，就是在特定的富含生物有机体的海水层去捕食。

许多浅海地区典型的滤食动物群都可以在深海找到代表，而这些都已经变成了捕食性生物。

浅海物种所发展出的高度过滤系统已经急剧退化。

而相对应的，它们演变出了主动或被动的猎物捕捉技巧，包括诱捕，抓取猎物，缠绕猎物或者是粘稠的触角。

⑤在海水的深处，动物们极有可能等待有机物或者猎物的到来，而不是主动出击去寻找它们（这样可以减少能量消耗）。

这会导致一种更加秘密的捕食方式，更加强调诱捕或者伸长的附属器官的进化，这样能增加动物控制和监控的活动水量。

有限的猎物来源产生另一个结果就是很多动物发展出一系列办法来处理和它们体型相比更大的有机物，这比同等的浅海区域生物能处理的生物大很多鱼群的牙齿和下颌逐渐开始变得很大。

在这些生物中，不仅它们的牙齿变得很大或者它们下颌变长，而且它们嘴通过高效地脱臼和下颌灵活咬合张的更大。

太大或太长的牙齿几乎没有办法把猎物切割成吞咽时合适的大小，鱼必须要将猎物整个吞下。

题目
1.The word "severe" in the passage is closest in meaning to
A.extreme
plex
C.basic
D.immediate
2. What can be inferred from paragraph 1 about why energy conservation is not a high priority for ocean animals in coastal waters during the spring?
A.Those animals are least active during the spring
B.Those animals have a plentiful supply of food
C.Those animals have to expend energy to avoid predators.
D.Those animals store energy during the colder seasons.
3. What can be inferred from paragraph 2 about fish?
A.Most fish feed on plankton.
B.Fish tend to avoid well-illuminated areas.
C.Most fish species are not filter-feeders.
D.Few fish species are successful in the near-surface layers.
4. According to paragraph 2, how do sardines and anchovies obtain food near the surface of the ocean?
A.They rely on the large quantities of food resources also available to local
carnivores.
B.They capture the larvae of some crustaceans.
C.They feed on the organisms left over by commercial fisheries.
D.They obtain algae by using their gills as filters.
5. In paragraph 1, the author compares pollen moved by wind with letters thrown off roofs in order to
A.explain why there are relatively few species of trees that depend on wind
pollination
pare natural, biological processes with human social practices
C.make a point about the probability of wind-blown pollen reaching a tree of
the same species
D.argue against the common assumption that the tallest trees are the most
likely to employ wind pollination
6. Paragraph 2 suggests that wind-pollinated plants do not have bright petals, nectar, and scent for which TWO of the following reasons? To receive credit, you must select TWO answers.
A.□They interfere with pollination by wind
B.□They are easily damaged by wind.
C.□They are unnecessary.
D.□They reduce the amount of pollen that can be produced.
7. The word "scarcity" in the passage is closest in meaning to
A.speed
B.variety
ck
D.size
8. According to paragraph 4,deep-water filter-feeders have adopted all of the following ways to obtain food EXCEPT
A.developing larger filtering systems
B.capturing prey using sticky tentacles
C.swimming up to the surface at feeding time
D.searching in ocean layers that contain a substantial amount of particles
9. Why does the author include the information that animals in the deep ocean place an emphasis on lures" and have evolved "elongated appendages”?
A.To argue against the view that animals in the deep ocean use more energy
to find food than do animals in shallow waters
B.To emphasize the importance of an am mars ability to control a large volume
of water
C.To identify some feeding strategies that animals have developed to minimize
their energy expenditure
D.To give examples of body structures that help those animals move quickly in
deep ocean waters
10. The phrase "coping with" in the passage is closest in meaning to
A.Absorbing
B.finding
C.approaching
D.managing
11. The word "flexible" in the passage is closest in meaning to
A.huge
B.adaptable
C.powerful
D.precise
12. According to paragraph 5, why do some fish swallow their prey whole?
A.Their teeth are too large to allow for cutting prey.
B.They have no jaw muscles to allow chewing.
C.Swallowing prey whole results in a higher net energy gain.
D.Chewing can cause their jaws to dislocate.
13. Look at the four squares [■] that indicate where the following sentence could be added to the passage.
Such a passive approach requires those animals to develop specialized methods of acquiring food.
Where would the sentence best fit? Click on a square [■] to add the sentence to the passage.
⑤[■]In the deeper waters of the oceans, there is a much greater tendency for animals to await the arrival of food particles or prey rather than to search them out actively (thus minimizing energy expenditure). [■] This has resulted in a more stealthy style of feeding, with the consequent emphasis on lures and/or the evolution of elongated appendages that increase the active volume of water controlled or monitored by the animal. [■] Another consequence of the limited availability of prey is that many animals have developed ways of coping with much larger food particles, relative to their own body size, than the equivalent shallower species can process. [■] Among the fishes there is a tendency for the teeth and jaws to become appreciably enlarged. In such creatures, not only are the teeth hugely enlarged and/or the jaws elongated but the size of the mouth opening may be greatly increased by making the jaw articulations so flexible that they can be effectively dislocated. Very large or long teeth provide almost no room for cutting the prey into a convenient size for swallowing; the fish must gulp the prey down whole.
14. Directions: An introductory sentence for a brief summary of the passage is provided below Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage This question is worth 2 points.Drag your answer choices to the spaces where they belong. To remove an answer choice, click on it.To review the passage, click VIEW TEXT
Ocean animals have developed various strategies for maximizing energy input from food.
Answer Choices
rge carnivores near the ocean surface feed mainly on organic matter left
over after it passes through the filters of the filter-feeders.
B.Even in deep ocean layers where prey is relatively hard to find, filter feeding
is still the least energetically-demanding method of obtaining food.
C.Animals in deeper water have evolved strategies and body structures that
allow them to use as little energy as possible in obtaining food.
D.Near the surface of the water, many animals obtain food by using specialized
body parts to filter plankton from the water.
E.Filter-feeding is more common in shallow water, where there is a higher
concentration of organic matter than there is in deeper water.
F.At deeper ocean levels plankton is relatively rare, requiring animals at those
levels to actively search for their food sources.
答案
1-5.A B C D D
6-10.D C C C D
11-13.B A B
14.CDE
背景知识
深海是地球上最极端的环境之一，包括高压、低温、黑暗和缺氧等极端条件。

尽管如此，深海生物展现出了惊人的适应能力，使它们能够在这些极端环境中生存。

以下是深海生物的一些适应策略：
1)高压适应：深海生物需要适应高压环境，其中水压可达到数百至数千个大气
压。

它们的细胞和组织通常具有特殊的结构和组织构造，以抵御高压的影响。

一些深海生物还具有特殊的骨骼或体液调节机制，以保持体内的相对稳定性。

2)低温适应：深海水温通常较低，但深海生物能够适应这种低温环境。

它们通
常具有适应低温的酶和蛋白质，以维持正常的生物化学反应。

此外，深海生物的细胞膜通常富含不饱和脂肪酸，以保持其流动性。

3)光适应：深海是一个黑暗的环境，没有太阳光照射。

深海生物可以通过生物
发光（生物发光现象），利用自身产生的光来进行照明、迷惑和吸引猎物。

一些深海生物还具有特殊的视觉器官和感知机制，如高度敏感的眼睛和感应器，以在黑暗中寻找食物和避免捕食。

4)营养适应：深海生物通常面临食物稀缺的问题。

它们可能具有适应性的摄食
策略，如过滤食物或捕食漂浮的有机物。

一些深海生物还可以依靠共生关系，
与其他生物合作以获取营养。

5)缺氧适应：深海底部通常缺乏氧气，但一些深海生物已经适应了这种缺氧环
境。

它们的细胞和组织通常具有高度的氧气亲和力和耐受力，以适应低氧条件。

一些深海生物还可以从化学能转化为能量，以维持其生存。