If you travel by a 1 across the center of Africa or South America, you fly over forests for thousands of kilometers. These great forests are the oceans of t 2 . There are thousands and thousands of kinds of plants and a 3 . However, the world's forests are getting s 4 all the time. In many places, we're cutting down the trees because we need wood and we need more farmland. Some people say that t 5 will not be any forest like these in 30 years. What will happen if they d 6 ? If we cut down our forests, a lot of plants and animals will disappear from the w 7 . In a lot of places the new farmland will soon look like the old desert. Crops will not grow there. It will not rain very often, and the weather will get very hot. Perhaps the climate (气候) of the world will c 8 . This will be d 9 for everyone in the world. That's w 10 we must take care of our forests. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
