专项练习：2021年考研英语基础模拟题（四十一）

发布时间：2020-10-25

英语是考研初试当中比较拉分的科目，历来令不少考生又爱又恨。许多考生的英语都有很大的进步空间，因此英语该如何学就成为了众多考生关心的重点。想要学好英语，实战经验很重要。下面，51题库考试学习网为大家带来考研初试英语科目的一些模拟试题，正在备考的小伙伴赶紧练起来吧。

Part B

Directions:

In the following article, some sentences have been removed. For Questions 41-45, choose the most suitable one from the lish A-G to fit into each of the numbered blank. There are two extra choices that do not fit in any of the gaps. Mark your answers on ANSWER SHEET 1. (10 points)

Rain forest structure is distinct from most other forest types because of its many layers of vegetation, referred to as strata. The lowest stratum is the understory, composed of palms, herbaceous plants (such as wild ginger), and tree seedlings and saplings. (41) _____________. Many have deep red coloring on the underside of their leaves to capture some of the scarce light that does manage to reach the forest understory. This red coloring enables understory plants to absorb light of different wavelengths than do the plants with rich, green-foliaged canopy, the umbrella-shaped upper structure of trees. Above the forest floor but below the canopy are one or more midstory strata, made up of woody plants, such as large shrubs and midsized trees.

The overstory is the canopy, in which the tree crowns form a continuous layer that captures the major part of the rainwater and sunlight hitting the forest. The height of the canopy varies from region to region and forest to forest, ranging from 20 to 50 m (65 to 165 ft). (42) ____________. Researchers use hot air balloons, cables, catwalks, towers, sophisticated tree-climbing gear, and even robots to study the millions of plants and animals that make their home high up in the forest canopy. Canopy researchers also use huge cranes that are dropped into the heart of the forest by helicopters. Suspended from the crane’s long, movable arm is a large cabin that functions as a mobile treetop laboratory. Moving from tree to tree, forest researchers collect specimens, conduct experiments, and observe life in the canopy frontier.

The highest stratum of the rain forest is made up of the emergent trees, those individuals that stick up above the forest canopy. Emergents, which do not form a continuous layer, are usually the giants of the forest, reaching heights of 35 to 70 m (115 to 230 ft) or more, and trunk sizes of over 2 m (6.6 ft) in diameter. (43) _____________. However, these trees tend to be so large that they collectively account for the vast majority of the woody mass, or biomass, of the forest.

The nicely ordered strata of the rain forest, including the continuous layer of the canopy, are regularly disturbed by naturally occurring events, such as falling trees. Trees in a rain forest canopy are often interconnected by vines, and a falling tree may pull as well as push other trees down with it, producing a domino effect of falling trees. The resulting opening in the forest canopy enables light to pour onto the forest floor. (44) _________________.

Other natural disturbances create even larger openings in the forest canopies. For example, along the hurricane belt in the Caribbean and the typhoon belt along the western Pacific, some forests are substantially altered when high winds and storms blow down hundreds of trees every few decades. (45) _________________. Scientists have found that these natural disturbances and the subsequent forest regeneration are a vital process that leads to healthy and diverse forests.

[A] New plants and animals then move into the area and begin to grow.

[B] Just 2 percent of the sunlight goes through the many layers of leaves and branches above, so understory plant species have developed special traits to cope with low light levels.

[C] On a smaller scale, large mammals, such as elephants, regularly destroy rain forest vegetation in the Congo River Basin in Africa.

[D] An understory of shorter trees and a lacework of woody vines, or lianas, produce a forest of such complex internal architecture that many animals, including some sizable ones, rarely or never descend to the ground.

[E] Less than one percent of the trees in the forest reside in the canopy and emergent layers.

[F] Because more light penetrates the canopy, however, the vegetation of the understory and forest floor is better developed than in the tropics.

[G] The rich, green canopy is teeming with life, and forest researchers have developed ingenious methods for accessing this mysterious ecosystem.

以上就是51题库考试学习网为大家带来的全部内容，希望能给大家一些帮助。51题库考试学习网提醒：在最后阶段，调整自己的心态也是非常重要的，每年都有考生临考前放弃，所以小伙伴们要注意不要给自己太大的压力哦。另外，小伙伴们如果还有其他关于考研信息的疑问，也可以留言咨询哦。

下面小编为大家准备了 研究生入学 的相关考题，供大家学习参考。

声明：本文内容由互联网用户自发贡献自行上传，本网站不拥有所有权，未作人工编辑处理，也不承担相关法律责任。如果您发现有涉嫌版权的内容，欢迎发送邮件至：contact@51tk.com 进行举报，并提供相关证据，工作人员会在5个工作日内联系你，一经查实，本站将立刻删除涉嫌侵权内容。