说到托福阅读备考，大家首先想到的肯定是OG和TPO。作为托福必不可少的备考神器，通过TPO练习来更好的适应考试的节奏。本文对TPO17 Symbiotic Relationships这篇文章的题材和部分题目进行了简单的分析，希望能够给正在备考托福阅读的大家带来一些参考的作用。
TPO17 Symbiotic Relationships
文章题材：生物科学——共生关系
常见词汇：
adaptation [.ædæp'teiʃən] n. 改编，改编成的作品，适应
organic [ɔ:'gænik] adj. 器官的，有机的，根本的，接近自然的
highlight ['hailait] n. 加亮区，精彩部分，最重要的细节或事件，闪光点
summary ['sʌməri] n. 摘要adj. 概要的，简略的
decay [di'kei] v. (使)衰退，(使)腐败，腐烂n. 衰退
devastated ['devəsteitid] adj. 毁坏的;极为震惊的 v. 毁坏;摧毁(deva
protect [prə'tekt] vt. 保护，投保
derive [di'raiv] v. 得自，起源，引申于
particular [pə'tikjulə] adj. 特殊的，特别的，特定的，挑剔的
rarity ['rɛərəti] n. 稀薄，稀有，珍品
易错题解析：
Paragraph 1: A symbiotic relationship is an interaction between two or more species in which one species lives in or on another species. There are three main types of symbiotic relationships: parasitism, commensalism, and mutualism. The first and the third can be key factors in the structure of a biological community; that is, all the populations of organisms living together and potentially interacting in a particular area.
1. Which of the following statements about commensalism can be inferred from paragraph 1?
○It excludes interactions between more than two species.
○It makes it less likely for species within a community to survive.
○Its significance to the organization of biological communities is small.
○Its role in the structure of biological populations is a disruptive one.
题型：推论题。答案是(D)
解析：“commensalism”做关键词定位至第二、三句。“There are three main types of symbiotic relationships: parasitism, commensalism, and mutualism. The first and the third can be key factors in the structure of a biological community.” 表明共有三种类型的共生关系，其中第一种和第三种是重要因素，进而推断出第二种commensalism不重要。所以C选项中，commensalism对于生物群落组织的意义不大，和原文意思相符，正确。
A项和B项与原文内容不符，C项说法错误。
易错选项：(D)。
Paragraph 3: At times, it is actually possible to watch the effects of natural selection in host-parasite relationships. For example, Australia during the 1940 s was overrun by hundreds of millions of European rabbits. The rabbits destroyed huge expanses of Australia and threatened the sheep and cattle industries. In 1950, myxoma virus, a parasite that affects rabbits, was deliberately introduced into Australia to control the rabbit population. Spread rapidly by mosquitoes, the virus devastated the rabbit population. 2The virus was less deadly to the offspring of surviving rabbits, however, and it caused less and less harm over the years. Apparently, 3genotypes (the genetic make-up of an organism) in the rabbit population were selected that were better able to resist the parasite.1Meanwhile, the deadliest strains of the virus perished with their hosts as natural selection favored strains that could infect hosts but not kill them. Thus, natural selection stabilized this host-parasite relationship.
6. According to paragraph 3, all of the following characterize the way natural selection stabilized the Australian rabbit population EXCEPT:
○The most toxic viruses died with their hosts.
○The surviving rabbits were increasingly immune to the virus.
○The decline of the mosquito population caused the spread of the virus to decline.
○Rabbits with specific genetic make-ups were favored.
题型：否定事实信息题。答案是(C)
解析：关键词“Natural selection” 定位整个段落，因为本段主要都在讲自然选择对于兔群的影响，C选项蚊子数量的减少，导致病毒传播下降。原文没有相关信息，因此是错误信息。
A项、B项、C项都是原文中的信息。
以上就是小编带来的托福阅读浅析之TPO17 Symbiotic Relationships,希望能够帮助大家进行备考。更多托福考试资讯请关注前程百利。
您还可能关注：
