托福阅读修辞目的题是阅读考试中比较常见的一种题型，tpo则是托福阅读备考最权威的材料，所以托福小编综合二者，为大家集中整理了tpo阅读中考察的修辞目的题及其对应的解析，供大家参考使用。本文带来的是TPO25-3的修辞目的题，一起来看看吧。
TPO25-3 The Evolutionary Origin of Plants
Paragraph 5:When plants pioneered the land, they faced a range of challenges posed by terrestrial environments. On land, the supportive buoyancy of water is missing, the plant is no longer bathed in a nutrient solution, and air tends to dry things out. These conditions favored the evolution of the structures that support the body, vessels that transport water and nutrients to all parts of plant, and structures that conserve water. The resulting adaptations to dry land include some structural features that arose early in plant evolution; now these features are common to virtually all land plant. They include roots or root like structures, a waxy cuticle that covers the surfaces of leaves and stems and limits the evaporation of water, and pores called stomata in leaves and stems that allow gas exchange but close when water is scarce, thus reducing water loss. Other adaptations occurred later in the transition to terrestrial life and now wide spread but not universal among plants. These include conducting vessels that transport water and minerals upward from the roots and that move the photosynthetic products from the leavesto the rest of the plant body and the stiffening substance lignin, which support the plant body, helping it expose maximum surface area to sunlight.
10. What purpose does paragraph 5 serve in the larger discussion of the origins of terrestrial plants?
○ To emphasize how long it took for ancestral plants to adjust to life on land
○ To disprove the argument that land plants adapted easily to their new terrestrial environment
○ To explain how plant colonization changed the physical environment of the terrestrial world
○ To describe how ancestral plants solved the problems they confirmed in colonizing
解析：问整段的目的，看开头，第一句讲当植物登上陆地以后，面临很多问题，再看最后一句， 说these include blabla，都是解决问题的方法。很明显，这段讲的是植物所面对的问题 和解决方法，所以正确答案是D。A的how long 和C的change the physical environment 都没讲。B有一定迷惑性，但原文从没讲过植物很容易适应环境，更别说disprove 了，B错。
[5] 当植物开拓陆地的时候，它们要面对一系列陆地环境带来的挑战。在陆地上，水中支撑植物的浮力消失，植物不能再漂浮在营养液里，空气会风干水分。这些条件有助于进化出那些用于支撑枝干的结构、运输水分和养分到植物各部分的导管以及储存水分的结构。对干旱陆地的适应结果包括一些在早期植物进化中所体现出的结构特征;现在，这些特征几乎在所有的陆生植物上都有所体现。其中包括根或者类似根的结构、覆盖茎叶表面能阻止水分蒸发的蜡质角质层以及茎叶上被称为气孔的小孔——气孔的存在可以保证气体的交换，并在水分缺失时关闭气孔从而防止水分的进一步流失。其他的适应机制在向陆地过渡过程中出现得较晚，现在体现在很多植物上，但并不是所有的植物。其中包括从根部向上运输水分和矿物质的导管，从叶片向植物其他部分输送光合作用产物的筛管以及用来支撑植物体、使得它以最大表面积接触阳光的硬化木质。
Paragraph 6:These adaptations allowed an increasing diversity of plant forms to exploit dry land. Life on land, however, also required new methods of transporting sperm to eggs. Unlike aquatic and marine forms, land plants cannot always rely on water currents to carry their sex cells and disperse their fertilized eggs. So the most successful groups of land plants are those that evolved methods of fertilized sex cell dispersal that are independent of water and structures that protest developing embryos from drying out. Protected embryos and waterless dispersal of sex cells were achieved with the origin of seed plants and the key evolutionary innovations that they introduced: pollen, seeds, and later, flowers and fruits.
12. Which of the following best describes the author’s presentation of the information about land plants?
○ the author provided and overview of the evolutionary relationships between specific species of algae and land plants
○ The author discusses the transformation plants underwent in the process of changing from an aquatic to a terrestrial environment
○ the author establishes a pattern of similarity between major land and water pant groups
○ The author resents evidence to support the hypothesis that plants first fully evolved in water before finding their way to land
解析：这道题问的很泛，问关于 land plants 作者是怎么写的，所以需要看不止一段，看各段开 头可知倒数三段是讲陆生植物的，讲了植物从水生到陆生的过程，于是正确答案是B。 这几段几乎没有讲到藻类，所以A错;也没有水生和陆生植物的比较，C错;至于D，按其说法根本就没讲陆生植物，是讲水生植物在登上陆地之前是如何 develop 的，不沾边。
[6] 这些适应机制保证了不断增加的植物形态的多样性，以便于它们去开拓干旱的陆地。然而，陆地上的生物也需要新的方法来受精。与水中和海洋中的形式不同，陆生植物无法总是依赖水流来携带生殖细胞或传播受精卵。因此，陆生植物中最成功的那几组植物都进化出了不依靠水也可以传播受精生殖细胞的方式和防止发育中的胚胎变干的结构。进化到种子植物时，保护胚胎以及在无水环境下传播生殖细胞的方式才得以实现，它们带来的关键进化创新的产物是：花粉、种子以及后来的花朵和果实。
以上就是托福阅读TPO25-3中的修辞目的题及其解析，大家可以在备考的时候参考复习，希望能够帮助大家的考前准备。最后前程百利祝大家都能取得理想的托福考试成绩。
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