您IP所在的地区,暂不支持官方真题素材

建议使用其他功能进行阅读练习

返回
小站备考
托福
托福阅读
Official47阅读真题

托福official47阅读第2篇Termite Ingenuity题目解析

展开
Termite Ingenuity
Tip:单击查看句义;划选/双击查生词
Termites, social insects which live in colonies that, in some species, contain 2 million individuals or more, are often incorrectly referred to as white ants . But they are certainly not ants. Termites, unlike ants, have gradual metamorphosis with only three life stage: egg, nymph, and adult. Ants and the other social members of their order, certain bees and wasps, have complete metamorphosis in four life stages; egg, larva, pupa, and adult. The worker and soldier castes of social ants, bees, and wasps consist of only females, all daughters of a single queen that mated soon after she matured and thereafter never mated again. The worker and soldier castes of termites consist of both males and females, and the queen lives permanently with a male consort. 

Since termites are small and soft-bodied, they easily become desiccated and must live in moist places with a high relative humidity. They do best when the relative humidity in their nest is above 96 percent and the temperature is fairly high, an optimum of about 79°F for temperate zone species and about 86°F for tropical species. Subterranean termites, the destructive species that occurs commonly throughout the eastern United States, attain these conditions by nesting in moist soil that is in contact with wood, their only food. The surrounding soil keeps the nest moist and tends to keep the temperature at a more or less favorable level. When it is cold in winter, subterranean termites move to burrows below the frost line.

Some tropical termites are more ingenious engineers, constructing huge above-ground nests with built-in “air conditioning” that keeps the nest moist, at a constant temperature, and well supplied with oxygen. Among the most architecturally advanced of these termites is an African species, Macrotermes natalensis. Renowned Swiss entomologist Martin Luscher described the mounds of this fungus-growing species as being as much as 16 feet tall, 16 feet in diameter at their base, and with a cement-like wall of soil mixed with termite saliva that is from 16 to 23 inches thick. The thick and dense wall of the mound insulates the interior microclimate from the variations in humidity and temperature of the outside atmosphere. Several narrow and relatively thin-walled ridges on the outside of the mound extend from near its base almost to its top.

According to Luscher, a medium-sized nest of Macrotermes has a population of about 2 million individuals. The metabolism of so many termites and of the fungus that they grow in their gardens as food helps keep the interior of the nest warm and supplies some moisture to the air in the nest. The termites saturate the atmosphere of the nest, bringing it to about 100 percent relative humidity, by carrying water up from the soil.

But how is this well-insulated nest ventilated? Its many occupants require over 250 quarts of oxygen (more than 1,200 quarts of air) per day. How can so much oxygen diffuse through the thick walls of the mound? Even the pores in the wall are filled with water, which almost stops the diffusion of gases. The answer lies in the construction of the nest. The interior consists of a large central core in which the fungus is grown, below it is “cellar” of empty space, above it is an “attic” of empty space, and within the ridges on the outer wall of the nest, there are many small tunnels that connect the cellar and the attic. The warm air in the fungus gardens rises through the nest up to the attic. From the attic, the air passes into the tunnels in the ridges and flows back down to the cellar. Gases, mainly oxygen coming in and carbon dioxide going out, easily diffuse into or out of the ridges, since their walls are thin and their surface area is large because they protrude far out from the wall of the mound. Thus air that flows down into the cellar through the ridges is relatively rich in oxygen, and has lost much of its carbon dioxide. It supplies the nest’s inhabitants with fresh oxygen as it rises through the fungus-growing area back up to the attic.

1.The author mentions “white ants” in the beginning of the passage in order to

你的答案:
正确答案:A

名师1对1,深度分析薄弱项,高效提分

去咨询
题目解析:
 后才能查看题目解析,还没有账号? 马上注册
【题目翻译】作者在文章的开头提到“白色蚂蚁”,以便 A:纠正对白蚁的常见误解 B:介绍白蚁只在某些生命阶段以蚂蚁的形式存在的观点。 C:认为并非所有的白蚁都是社会性昆虫。 D:说明生活在群落中的昆虫种类繁多。 【判定题型】:根据题目问法,题目询问white ants组成或构成方式/段落与段落的关系/某一段在全文中所起的作用,故判断本题为组织结构题。 【内容分析】原文But they are certainly not ants,说明作者想要表明白蚁并不是人们认为的蚂蚁。 【选项分析】 A:纠正对白蚁的常见误解。符合文意,正确 B:介绍白蚁只在某些生命阶段以蚂蚁的形式存在的观点。不符,错误 C:认为并非所有的白蚁都是社会性昆虫。不符,错误 D:说明生活在群落中的昆虫种类繁多。不符,错误

学习页面

Medi

terr

anean

加强 + 政府 + 名词后缀

加强的政府——管理

原文例句

加入生词

本文生词 0

色块区域是你收藏过的生词;

查询次数越多,颜色越深哦~

显示文中生词

登录后才能收藏生词哦,现在登录注册>

本文重点词 45

文中加粗单词为本文重点词;

根据词频与核心词范围精心挑选,托福考试必掌握词汇。

显示文中重点词
学习本文词汇

文中划选/双击的生词、加粗重点词已收纳至词盒

可随时点击词盒查看哦~

只有在词句精学模式下才能开启词盒功能哦~

我知道了

词盒
收藏
笔记
我的笔记
5000
保存
反馈