假设你是李华。你班上周日开展了以“美化城市环境，倡导低碳生活”为宗旨的志愿者活动。活动内容包括：上午去郊区植树；下午去广场宣传，分发传单（leaflet）。你的美国朋友 George 来信想了解此活动，请你写封回信按照以下要求介绍这个活动：
I am glad to receive your letter asking for my introduction about our class voluntary activity. I’m writing to tell you something about it.
Last Sunday, our class launched a voluntary activity, the theme of which is to make the city more beautiful and advocate a low carbon lifestyle. In the morning, we went to plant trees in the suburbs. In the afternoon, we went to the streets to hand out leaflets, raising people’s awareness of environmental protection.
Most of the students think highly of the activity, which will surely have a positive effect on our daily life.
As far as I’m concerned, it’s everyone’s duty to protect the environment. As long as there is the possibility of saving our planet, do take action now before it is too late. Low carbon living is surely a way of great significance.