随着科技的发展，几乎每个高中生都有自己的微信号，交流特别方便。但很多学生花太多的时间用微信和朋友聊天。假设你是学生会主席李华，请你以学生会的名义给全校学生写一份英文倡议书，倡议大家减少使用社交媒体的时间。内容包括：
1.倡议的目的；
2.过度使用社交媒体的危害；
3.发出倡议。
注意：
1.词数100左右；
2.可适当增加细节，以使行文连贯；
3.开头和结尾已给出，不计入总词数；
4.参考词汇：社交媒体social media.
Dear all，
   I'm Li Hua，chairman of the Students' Union.____________
Students' Union

【考点】提纲作文；倡议书；科技生活．

【答案】Dear all，
I'm Li Hua，chairman of the Students' Union.I'm writing to advocate all the students to reduce the time of using social media on behalf of the Students' Union of our school.
Recent years have witnessed the high development of science and technology，bringing great convenience to our daily communication.However it is not uncommon that quite a few students attach too much importance to their "virtual" friends on social media，influencing their relationship with friends in real life.Worse still，social media has occupied too much of their spare time，even their study time，doing harm to their academic results.
Please be aware of the problem.Let's use social media properly and limit our time on it.
Students' Union