1 . Rainforests are home to all sorts of medicinal plants, food, birds and animals. Can you believe that a single bush (灌木丛) in the Amazon may have more species of ants than the whole of Britain! About 480 kinds of trees may be found in just one hectare of rainforest.
Rainforests are the lungs (肺) of the planet—storing carbon dioxide (CO2) and producing oxygen (O2). Rainforests have their own perfect system for ensuring their own living; the tall trees make a canopy (树冠层) of branches and leaves which protect themselves, smaller plants, and the forest animals from heavy rain, serious dry heat from the sun and strong winds.
Amazingly, the trees’ 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 live 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 very 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 produce 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 (湿气) of large rainforests contributes to the formation of rainclouds that may travel to other countries in need of rain.
1. What can we learn about rainforests from Paragraph 1?| A．They produce oxygen. | B．They cover a large area. |
| C．They provide food for animals. | D．They are rich in wildlife. |
| A．mixed | B．clear | C．organized | D．dead |
| A．The Law of the Rainforest | B．Life-Giving Rainforests |
| C．Animals in the Amazon | D．Weather in Rainforests |
