Directions: For this part, you are allowed 30 miniutes to write a composition on the title:make our city greener,your composition should be based on the following outline:
　　1：城市绿色的状况。
　　2：绿化的好处（如：清洁空气，美化城市，改善气候......）。
　　3：怎样才能实现绿化。

　　范文
　　Recent efforts toward the greening of our cities have achieved much, although the results are still far from satisfactory. In recent years many trees have been planted in the cities and much care has been taken of the planted trees. In spite of all this, the greening process is relatively slow compared with cities in many other countries. For example, the green space available on average to each Shanghai citizen is only 0.4 Mu while every Londoner has more than 20 Mu.
　　We can benefit much from making our cities greener by planting trees. First, trees absorb carbon dioxide to produce oxygen which is essential to the health of human beings. Second, trees and other greenery make our cities more beautiful. Third, trees can also improve the climate of the cities.
　　Since we can get so much from making our cities greener, we should spare no effort to do that. We should plant more trees and take better care of them. We also should not cut down the trees. In a word, we should do everything to add to the greening of our cities.