One reaction to all the concern about tropical deforestation (砍伐森林) is a blank stare that asks the question, "Since I don't live there, what does it have to do with me?"
The answer is that your way of life, wherever you live in the world, is tied to the tropics (热带地区) in many ways. If you live in a house, wash your hair, eat fruits and vegetables, drink soda, or drive a car, you can be certain that you are affected by the loss of tropical forests.
Biologically, we are losing the richest regions on earth when, each minute, a piece of tropical forest, the size of ten city blocks, disappears. As many as five million species of plants, animals, and insects (40 to 50 percent of all living things) live there, and are being lost faster than they can be found and described. Their loss is immeasurable.
Take rubber for example. For many uses, only natural rubber from trees will do. Synthetics are not good enough. Today over half the world's commercial rubber is produced in Malaysia and Indonesia, while the Amazon's rubber industry produces much of the world's four million tons. And rubber is an important material in making gloves, balloons, footwear and many sporting goods. Thousands of other tropical plants are valuable for their industrial use.
Many scientists strongly believe that deforestation contributes to the greenhouse effect – or heating of the earth from increased carbon dioxide in the atmosphere. As we destroy forests, we lose their ability to change carbon dioxide into oxygen.
Carbon dioxide levels could double within the next half-century, warming the earth by as much as 4.5 degrees. The result A partial melt-down of polar ice caps, raising sea levels as much as 24 feet; even 15 feet could threaten anyone living within 35 miles of the coast. Unbelievable? Maybe. But scientists warn that by the time we realize the severe effects of tropical deforestation, it will be 20 years too late.
Can tropical deforestation affect our everyday lives? Now, you should have got the answer.
68. The underlined word "synthetics" in Paragraph 4 probably means .
A. natural rubber B. tropical materials
C. man-made material D. commercial rubber
69. In the last paragraph the author tries to .
A. tell people how to avoid the tropical deforestation
B. persuade people to buy something synthetic
C. show us how important it is to protect the tropical forests
D. let people realize the effect of tropical deforestation
70. According to the passage, which of the following is NOT true?
A. The forests are losing their function in turning carbon dioxide into oxygen.
B. Many of our daily uses are related to the tropical forests.
C. Tropical plants can be used to make industrial products.
D. High carbon dioxide levels will make the earth warmer.
71. Which of the following might be the best title for the passage?
A. Tropical Forests B. Saving the Tropical Forests
C. Tropical Forests and Our Life D. The Greenhouse Effects