托福阅读生物类背景知识及真题
生物类话题是托福阅读中最常见话题之一，当然对于生物的考察也不仅仅局限于陆地，还会延伸至海洋，说到海洋生物，大家对珊瑚(coral)一定并不陌生，但是珊瑚礁(coral reef)是如何形成、又如何分类呢?今天我们就一起来看一看托福阅读生物类背景知识及真题。
托福阅读生物类背景知识
珊瑚礁
珊瑚礁(coral reef)是指造礁石珊瑚群体死后其遗骸(remains)构成的岩体。珊瑚礁的主体是由珊瑚虫(polyp)组成的。珊瑚虫是海洋中的一种腔肠动物在生长过程中能吸收海水中的钙和二氧化碳，然后分泌出石灰石(limestone)，变为自己生存的外壳。每一个单体的珊瑚虫只有米粒那样大小，它们一群一群地聚居在一起，一代代地新陈代谢(metabolism)，生长繁衍，同时不断分泌出石灰石，并粘合在一起。这些石灰石经过以后的压实、石化，形成岛屿和礁石，也就是所谓的珊瑚礁(coral reef)。
达尔文根据礁体与岸线的关系，划分出岸礁(fringing reef)、堡礁(barrier reef)和环礁(atoll)。
fringing reef
暗礁
沿大陆(mainland)或岛屿(island)岸边(shore)生长发育，亦称裙礁或边缘礁。现代最长的岸礁沿红海沿岸发育，绵延约2700多公里，分布水深约36米。中国台湾恒春半岛和海南岛沿岸也有岸礁发育。
barrier reef
堡礁
又称堤礁，是离岸有一定距离的堤状礁体，它与陆地隔以泻湖(环礁湖)(lagoon)。现代规模最大的堡礁是澳大利亚昆士兰大堡礁，全长约2000公里，分布水深约30米。
atoll
环礁
礁体呈环带状围绕泻湖(lagoon)，有的与外海有水道相通。环礁直径在几百米至几十公里，形态多样。已知的环礁有330个之多,主要分布在西太平洋的信风带和印度洋热带海域。环礁多坐落在大洋火山锥上，孤立于汪洋大海之中，展布受洋底火山(volcano)作用的控制，某些也可在大陆架(continental shelf)上见到。环礁礁坪上常有灰砂(砾)岛或礁岩岛，统称为珊瑚岛。
马绍尔群岛上的夸贾林环礁和马尔代夫群岛的苏瓦迪瓦环礁，面积都在1800平方公里以上，是世界上最大的两个环礁。南海发育的环礁颇具特色，有泻湖全被封闭的玉琢礁;有泻湖与外海有3个通道的华光礁;还有多通道开放式的永乐环礁，半月形全开放式的宣德环礁。永乐环礁和宣德环礁均发育有灰砂岛和礁岩岛，其中最大的灰砂岛是永兴岛，面积1.85平方公里。
托福阅读真题练习：蝴蝶
托福阅读文本：
Butterflies are among the most extensively studied insects — it is estimated that 90 percent of the world's species have scientific names. As a consequence, they are perhaps the best group of insects for examining patterns of terrestrial biotic diversity and distribution. Butterflies also have a favorable image with the general public. Hence, they are an excellent group for communicating information on science and conservation issues such as diversity.
Perhaps the aspect of butterfly diversity that has received the most attention over the past century is the striking difference in species richness between tropical and temperate regions. For example, in 1875 one biologist pointed out the diversity of butterflies in the Amazon when he mentioned that about 700 species were found within an hour's walk, whereas the total number found on the British islands did not exceed 66, and the whole of Europe supported only 321. This early comparison of tropical and temperate butterfly richness has been well confirmed.
A general theory of diversity would have to predict not only this difference between temperate and tropical zones, but also patterns within each region, and how these patterns vary among different animal and plant groups. However, for butterflies, variation of species richness within temperate or tropical regions, rather man between them, is poorly understood. Indeed, comparisons of numbers of species among the Amazon basin, tropical Asia, and Africa are still mostly "personal communication" citations, even for vertebrates. In other words, unlike comparison between temperate and tropical areas, these patterns are still in the documentation phase.
In documenting geographical variation in butterfly diversity, some arbitrary, practical decisions are made. Diversity, number of species, and species richness are used synonymously;little is known about the evenness of butterfly distribution. The New World butterflies make up the preponderance of examples because they are the most familiar species. It is hoped that by focusing on them, the errors generated by imperfect and incomplete taxonomy will be minimized.
托福阅读题目：
1. Which aspect of butterflies does the passage mainly discuss?
(A) Their physical characteristics
(B) Their names
(C) Their adaptation to different habitats
(D) Their variety
2. The word "consequence" in line 2 is closest in meaning to
(A) result
(B) explanation
(C) analysis
(D) requirement
3. Butterflies are a good example for communicating information about conservation issues
because they
(A) are simple in structure
(B) are viewed positively by people
(C) have been given scientific names
(D) are found mainly in temperate climates
4. The word "striking" in line 8 is closest in meaning to
(A) physical
(B) confusing
(C) noticeable
(D) successful
5. The word "exceed" in line 11 is closest in meaning to
(A) locate
(B) allow
(C) go beyond
(D) come close to
6. All of the following are mentioned as being important parts of a general theory of diversity EXCEPT
(A) differences between temperate and tropical zones
(B) patterns of distribution of species in each region
(C) migration among temperate and tropical zones
(D) variation of patterns of distribution of species among different animals and plants
7. The author mentions tropicalAsia in lines 19 as an example of a location where
(A) butterfly behavior varies with climate
(B) a general theory of butterfly diversity has not yet been firmly established
(C) butterflies are affected by human populations
(D) documenting plant species is more difficult than documenting butterfly species
8. Which of the following is NOT well understood by biologists?
(A) European butterfly habitats
(B) Differences in species richness between temperate and tropical regions
(C) Differences in species richness within a temperate or a tropical region
(D) Comparisons of behavior patterns of butterflies and certain animal groups
9. The word "generated" in line 26 is closest in meaning to
(A) requested
(B) caused
(C) assisted
(D) estimated
托福阅读答案：
DABCC CBCB
托福阅读真题练习：海洋文化
托福阅读文本：
The Native American peoples of the north Pacific Coast created a highly complex maritime culture as they invented modes of production unique to their special environment. In addition to their sophisticated technical culture, they also attained one of the most complex social organizations of any nonagricultural people in the world.
In a division of labor similar to that of the hunting peoples in the interior and among foraging peoples throughout the world, the men did most of the fishing, and the women processed the catch.
Women also specialized in the gathering of the abundant shellfish that lived closer to shore. They collected oysters, crabs, sea urchins, mussels, abalone, and clams, which they could gather while remaining close to their children. The maritime life harvested by the women not only provided food, but also supplied more of the raw materials for making tools than did fish gathered by the men. Of particular importance for the native tool kit before the introduction of metal was the wide knife made from the larger mussel shells, and a variety of cutting edges that could be made from other marine shells.
The women used their tools to process all of the fish and marine mammals brought in by the men. They cleaned the fish, and dried vast quantities of them for the winter. They sun-dried fish when practical, but in the rainy climate of the coastal area they also used smokehouses to preserve tons of fish and other seafood annually. Each product had its own peculiar characteristics that demanded a particular way of cutting or drying the meat, and each task required its own cutting blades and other utensils.
After drying the fish, the women pounded some of them into fish meal, which was an easily transported food used in soups, stews, or other dishes to provide protein and thickening in the absence of fresh fish or while on long trips. The woman also made a cheese-like substance from a mixture of fish and roe by aging it in storehouses or by burying it in wooden boxes or pits lined with rocks and tree leaves.
托福阅读题目：
1. Which aspect of the lives of the Native Americans of the north Pacific Coast does the passage
mainly discuss?
(A) Methods of food preservation
(B) How diet was restricted by the environment
(C) The contributions of women to the food supply
(D) Difficulties in establishing successful farms
2. The word "unique" in line 2 is closest in meaning to
(A) comprehensible
(B) productive
(C) intentional
(D) particular
3. The word "attained" in line 3 is closest in meaning to
(A) achieved
(B) modified
(C) demanded
(D) spread
4. It can be inferred from paragraph 1 that the social organization of many agricultural peoples is
(A) more complex than that of hunters and foragers
(B) less efficient than that of hunters and foragers
(C) more widespread than that of hunters and foragers
(D) better documented than that of hunters and foragers
5.According to the passage , what is true of the "division of labor" mentioned in line 5?
(A) It was first developed by NativeAmericans of the north Pacific Coast.
(B) It rarely existed among hunting
(C) It was a structure that the Native Americans of the north Pacific Coast shared with many other
peoples.
(D) It provided a form of social organization that was found mainly among coastal peoples.
6. The word "abundant" in line 7 is closest in meaning to
(A) prosperous
(B) plentiful
(C) acceptable
(D) fundamental
7.All of the following are true of the north Pacific coast women EXCEPT that they
(A) were more likely to catch shellfish than other kinds of fish
(B) contributed more materials for tool making than the men did
(C) sometimes searched for food far inland from the coast
(D) prepared and preserved the fish
8. The word "They" in line 16 refers to
(A) women
(B) tools
(C) mammals
(D) men
9. The NativeAmericans of the north Pacific Coast used smokehouses in order to
(A) store utensils used in food preparation
(B) prevent fish and shellfish from spoiling
(C) have a place to store fish and shellfish
(D) prepare elaborate meals
10. The wore "peculiar" in line 19 is closest in meaning to
(A) strange
(B) distinctive
(C) appealing
(D) biological
11. All of following are true of the cheese-like substance mentioned in paragraph 4 EXCEPT that
it was
(A) made from fish
(B) not actually cheese
(C) useful on long journeys
(D) made in a short period of time
托福阅读答案：
CDAAC BCABB D
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