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.
正确答案:BDE
译文
In the open sea, animals can often find food reliably available in particular regions or seasons (e.g., in coastal areas in springtime). 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)。 取消收藏 收藏句子 In these circumstances, animals are neither constrained to get the last calorie out of their diet nor is energy conservation a high priority. 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。 取消收藏 收藏句子 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. 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。 取消收藏 收藏句子 To survive at those levels, animals must maximize their energy input, finding and eating whatever potential food source may be present. 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。 取消收藏 收藏句子 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。
In 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. 在接近表层的地方,有许多大型、快速的食肉动物,以及种类繁多的浮游动物,它们以浮游生物(小型的、自由漂浮的植物或动物)为食,这些浮游动物通过过滤流经特殊解剖结构的水流来获取浮游生物。 取消收藏 收藏句子 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. 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。 取消收藏 收藏句子 Even fishes can become successful filter-feeders in some circumstances. 即使在有些情况下,鱼也可以变为成功的滤食动物。 取消收藏 收藏句子 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. 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。 取消收藏 收藏句子 These small fishes use their gill filaments to strain out the algae that dominate such areas. 这些小鱼会用它们的鳃丝过滤这个区域主要的藻类。 取消收藏 收藏句子 Sardines and anchovies provide the basis for huge commercial fisheries as well as a food resource for large numbers of local carnivores, particularly seabirds. 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。 取消收藏 收藏句子 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. 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。 取消收藏 收藏句子 在接近表层的地方,有许多大型、快速的食肉动物,以及种类繁多的浮游动物,它们以浮游生物(小型的、自由漂浮的植物或动物)为食,这些浮游动物通过过滤流经特殊解剖结构的水流来获取浮游生物。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。
Filtering 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. 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。 取消收藏 收藏句子 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. 每立升海水至少要含有 2.5 微克的微小有机物,才能为滤食性浮游生物提供净能量摄入。 取消收藏 收藏句子 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. 在大多数沿海区域都能轻松超过这个数值,但在深海,有机物含量从几乎为零到每立方升约 7 微克不等。 取消收藏 收藏句子 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. 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。 取消收藏 收藏句子 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。每立升海水至少要含有 2.5 微克的微小有机物,才能为滤食性浮游生物提供净能量摄入。在大多数沿海区域都能轻松超过这个数值,但在深海,有机物含量从几乎为零到每立方升约 7 微克不等。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。
There 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. 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。 取消收藏 收藏句子 Another solution for such animals is to forage in particular layers of water where the particles may be more concentrated. 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。 取消收藏 收藏句子 Many of the groups of animals that typify the filter-feeding lifestyle in shallow water have deep-sea representatives that have become predatory. 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。 取消收藏 收藏句子 Their filtering systems, which reach such a high degree of development in shallow-water species, are greatly reduced. 浅海物种所发展出的高度过滤系统已经急剧退化。 取消收藏 收藏句子 Alternative methods of active or passive prey capture have been evolved, including trapping and seizing prey, entangling prey, and sticky tentacles. 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。 取消收藏 收藏句子 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。
[■]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). 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)。 取消收藏 收藏句子 [■] 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. 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。 取消收藏 收藏句子 [■] 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. 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 取消收藏 收藏句子 [■] Among the fishes there is a tendency for the teeth and jaws to become appreciably enlarged. 鱼群的牙齿和下颌逐渐开始变得很大。 取消收藏 收藏句子 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. 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。 取消收藏 收藏句子 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. 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。 取消收藏 收藏句子 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。