夜幕降临,灯光闪烁。我打开电脑进入QQ聊天室。刚好圆锥体上线,我迫不及待地与它聊了起来。“圆锥体,你好!明天的数学课我们要学习有关你的知识,我要预习一下,你能给我指点指点吗?”“你好!你有什么问题尽管提,我会助你一臂之力的。”我马上在屏幕上打出一行字:“那先请你介绍一下,你有哪些特征?”“我呀,特征可不一般呢!我是立体图形的一种。哎呀,还是请你观察一下我的模型,你会有所发现的。”我拿起圆锥体模型,左瞧瞧右瞧瞧。哎?圆锥体是由一个圆形的底面与一个曲面组 Night falls, the lights flash. I opened the computer into the QQ chat room. Just cone on the line, I can not wait to talk to it. “Cone, hello! Tomorrow’s math class we want to learn about your knowledge, I want to pre-order, can you give me some advice? ” “Hello! Do you have any problem to mention, I will help Your hand. ”I immediately typed a line on the screen: “ Then I would like to introduce you, what are your characteristics? ”“ I ah, the characteristics can be unusual! I was a stereoscopic graphics. Or do you have a look at my model and you will notice it. ”" I picked up the cone model and looked left and right. Hey? The cone is composed of a circular bottom surface and a surface group