Directions: For this part, you are allowed thirty minutes to write all open letter to the major of the city based on the following situation:

You should write at least 150 words, and base your composition on the outline given below:

1. 1.近年来,本市空气污染情况越来越严重

2.你认为造成空气污染的主要污染源在哪里?应该采取哪些措施?

3.呼吁所有市民积极行动起来,治理空气污染