With the development of science and technology，great changes have taken place in our world. People would like to have a better life and a better future for their children，so there are a lot of people 1 from the countryside into the cities every year，hoping to get more in the modern world. This brings more people and makes the city 2 . It means more factories，more products and the 3 use of man-made materials. This increasing industrialization （工业化） has caused a big problem in our world.
In the old days，people once enjoyed clean air，pure water and 4 food. However，as our technological achievements have grow n in the last twenty years，5 has become a serious problem. Our environment is being polluted badly in many ways and people cannot stop it at once. The 6 is that pollution is caused by man— by too much strong wish for a modern way of life.
Isn't it time we stop to 7 ourselves where we are going— and why？It makes one think of the story about the pilot who 8 his passengers on the plane over the loudspeaker，"I've got good news and bad news. The good news is that we're 9 at 530 miles per hour. The bad news is that we're 10 and don't know where we're going. " It's a sad fact that this becomes a true story when we talk about our modern world.
