問題詳情：
Rainforests are home to a rich variety of medicinal plants, food, birds and animals. Can you believe that a single bush（灌木叢）in the Amazon may have more species of ants than the whole of Britain! About 480 varieties of trees may be found in just one hectare of rainforest.
Rainforests are the lungs of the planet-storing vast quantities of carbon dioxide and producing a significant amount of the world's oxygen. Rainforests have their own perfect system for ensuring their own survival; the tall trees make a canopy（樹冠層）of branches and leaves which protect themselves, smaller plants, and the forest animals from heavy rain, intense dry heat from the sun and strong winds.
Amazingly, the trees grow in such a way that their leaves and branches, although close together, never actually touch those of another tree. Scientists think this is the plants' way to prevent the spread of any tree diseases and make life more difficult for leaf-eating insects like caterpillars. To survive in the forest, animals must climb, jump or fly across the gaps. The ground floor of the forest is not all tangled leaves and bushes, like in films, but is actually fairly clear. It is where dead leaves turn into food for the trees and other forest life.
They are not called rainforests for nothing! Rainforests can generate 75%of their own rain. At least 80 inches of rain a year is normal-and in some areas there may be as much as 430 inches of rain annually. This is real rain-your umbrella may protect you in a shower, but it won't keep you dry if there is a full rainstorm. In just two hours, streams can rise ten to twenty feet. The humidity（溼氣）of large rainforests contributes to the formation of rainclouds that may travel to other countries in need of rain.
12．What can we learn about rainforests from the first paragraph?
A．They produce oxygen. B．They cover a vast area.
C．They are well managed. D．They are rich in wildlife.
13．Which of the following contributes most to the survival of rainforests?
A．Heavy rains B．Big trees.
C．Small plants. D．Forest animals.
14．Why do the leaves and branches of different trees avoid touching each other?
A．For more sunlight. B．For more growing space.
C．For self-protection. D．For the detection of insects.
15．What can be a suitable title for the text?
A．Life-Giving Rainforests B．The Law of the Jungle
C．Animals in the Amazon D．Weather in Rainforests
【回答】
12．D
13．B
14．C
15．A
【分析】
本文是說明文。熱帶雨林被稱爲“世界上最大的*房”，因爲超過25%的現代*物是由其植物提煉。熱帶雨林也享有“地球之肺”的美譽，因其植物的光合作用淨化地球空氣的能力尤爲強大。僅亞馬遜熱帶雨林產生的氧氣就佔全球氧氣總量的1/3。
12．細節理解題。根據第一段Rainforests are home to a rich variety of medicinal plants, food, birds and animals.得知，熱帶雨林蘊藏了豐富多*的*用植物、食物以及鳥禽猛獸。可知，熱帶雨林有豐富的野生動物，故選D。
13．細節理解題。根據第二段Rainforests have their own perfect system for ensuring their own survival; the tall trees make a canopy（樹冠層）of branches and leaves which protect themselves, smaller plants, and the forest animals from heavy rain, intense dry heat from the sun and strong winds.得知，熱帶雨林有自己完美的生存體系，高大的樹木有枝幹，樹葉的樹冠層保護樹木本身、小植物、動物們免受大雨和太陽強風帶來的乾燥熱浪的傷害。可知，大樹有助於熱帶雨林生存，故選B。
14．推理判斷題。根據第三段Scientists think this is the plants' way to prevent the spread of any tree diseases and make life more difficult for leaf-eating insects like caterpillars.得知，科學家們認爲這是植物阻止任何樹木疾病擴散和讓比如毛毛蟲這種食用樹葉的昆蟲難以生存。可以判斷出不同樹木的樹葉和樹枝避免彼此觸碰是爲了自我保護，故選C。
15．主旨大意題。本文首先講述了熱帶雨林蘊藏了豐富多*的*用植物、食物以及鳥禽猛獸。其次，熱帶雨林就是地球的肺——它吸納了大量的二氧化碳，並製造了全球氧氣的很大部分。然後，雨林可以自我形成所需降雨的75%，而龐大的熱帶雨林溼氣則可以形成雨雲，這些雨雲則可以飄往那些缺雨水的國家。可以判斷出本文最佳標題是“給予生命的熱帶雨林”，故選A。
知識點：自然
題型：閱讀理解
