Unit 2 Topic 2 Section C 课件 初中英语仁爱版九年级上册（2021年）.pptx

Unit 2 Saving the Earth Topic 2 All these problems are very serious

Section C; The earth is about 4,600 million years. 1 / ?m?dn / man has lived on the earth for only 35,000 years. But 2 /?dj??r??/ that time, human beings have changed our planet in many ways. Many of the things that we have done are good, 3 more are not good for the earth. Water pollution. Factories have 4 (pollution) that land and the water. As a result, many rivers and lakes are now 5 (die). Air pollution. In big cities, as well 6 cars, trucks and buses are the main cause of air pollution. Mexico city used to be a beautiful sunny 7 /?k?p?tl /, but today it is always covered by thick brown clouds. Soil pollution. In order to have a good harvest, most of the farmers use chemicals too 8 (many) in their fields. Hope for the