The Amazon Rainforest covers 6million square kilometers of jungle and river and spans over eight countries，half of which is in Brazil．It is home to millions of species of vegetation and animals，some of which are still being discovered today．It is also the world's largest supplier of oxygen and is a treasure chest for medical researchers who are experimenting with different plants in hopes of finding cures for diseases like cancer and AIDS．However，the world is at risk of losing this rich rainforest because of deforestation caused by the actions of loggers，farmers and settlers．

The Amazon Basin has lost 20% of its rainforest since 1970．Cattle farmers have continuously cleared the land for cows to eat on～and crop farmers have begun to"slash and burn"，a farming method that involves cutting down forests and burning the land to make it suitable for agricultural purpose．The problem with doing this in the Amazon，however，is that the soil is not rich enough to support multiple harvests．Loggers have been cutting down trees for timber，and settlers have been intruding on the land，further decreasing its size．

One reason why the shrinkage（碱少 ）of the Amazon causes such alarm is that it is the world's largest absorber of carbon dioxide．With the continuous destruction of the Amazon Rainforest，global warming becomes more of a threat．It is up to each individual to protest the destruction of the Amazon by making the world know something about this environmental disaster．

29．This article shows that the Amazon-Rainforest___．

A．is becoming smaller and smaller

B．was once shrinking but is growing now

C．has been of the same size for the past ten years

D．is a paradise for those who get serious diseases

30．The underlined phrase"slash and burn"in Para 2refers to___．

A．the phenomenon of the forest catching fire

B．the technique people use to get more farmland

C．the way logger