古希腊著名数学家欧几里德通过对当时已有的几何学知识的搜集、鉴别与梳理。以其独创的公理化方法，完成巨著《几何原本》，使零散的知识由此系统化为演绎的知识体系，实现了科学史上的重大创新。欧几里德实现原有几何知识的系统化，说明
①事物本身的联系具有系统性           ②联系的系统性根源于主观创造        
③事物之间的系统联系是自我呈现的        ④科学理论是对事物联系系统性的创造性反映

下列叙述中，正确的是（　　）

选出你听到的图片（  ）

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。错误仅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(\)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。

Withthe growing popularity of the Internet, more and more children are addicted toplay online games day and night. It does harm not only to their health,especial to their eyes, but also to their studies.

Comparingwith online games, many traditional games, like hide­and­seek, benefits kidsmentally and physically. They were ever popular to several generations, whichnot only learned something valuable but also had fun playing the games.Therefore, the games are dying away now.

Personally,I think teachers and parents should take measure to limit their children'sInternet time. Let children to know the harm of online games and the benefitsof traditional games. Help children judge the healthy and unhealthy games.What's more, we should often organize events for children in which traditionalgames played.

下列式子中，是最简二次根式的是（   ）