假定你是李華，你們學校在3月22日"世界水日"來臨之際將舉辦一系列活動。請寫一封郵件給學校英語外教Mr.Green，請他為本校學生開設講座。郵件的內容包括：
1.講座主題：廢水處理與利用；
2.講座目的；
3.講座時間及時長。
注意：
1.詞數80左右；
2.可以適當增加細節，以使行文連貫；
3.開頭和結尾已給出，不計入總詞數。
Dear Mr.Green，
________________
Yours，
Li Hua

【考點】提綱作文．

【答案】Dear Mr.Green，
    With World Water Day around the comer，our school is planning to hold a series of activities.I'm writing to invite you to give us a lecture on the topic of wastewater disposal and utilization.
    The lecture will be held in our school hall from 4：00 to 5：30 on the afternoon of March 22.We hope it can arouse students' awareness of water crisis as well as develop the habit of water recycling.If everyone can make good use of water，we together can make a big difference.
    I would be grateful if you could accept my invitation.
Yours，
Li Hua