关于能源和材料，下列说法中正确的是（　　）

亚非文明古国的共同特点是（   ）

①地处大河流域

②对外进行军事扩张

③以农业经济为主

④建立统一的奴隶制国家

⑤实行奴隶制民主政治

假定英语课上老师要求同桌之间交换修改作文，请你修改你同桌写的以下作文。文中共有10处语言错误，每句中最多有两处。错误涉及一个单词的增加、删除或修改。

增加：在缺词处加一个漏字符号(∧)，并在其下面写出该加的词。

删除：把多余的词用斜线(\)划掉。

修改：在错的词下画一横线，并在该词下面写出修改后的词。

注意：1)每处错误及其修改均仅限一词；

2)只允许修改10处，多者(从第11处起)不计分。

Dear Editor,

I'm the boy student in a key middle school in our city. I fond of play the piano. It is known by us that the college entrance examination is approaching. I must get good prepared for it. So I have only fifteen minutes to play the piano on every day. I don't want to give up my favorite, and my parents forbade me to continue playing it. They think it a waste of time to do it now. How do you think of it? Could you give me some advices on how to deal with the problem? I am looking forward to your early reply.

Thank you.

John