From 2a9d6489284cd94b2ba7e25e11ce241f51ed7907 Mon Sep 17 00:00:00 2001
From: 123456 <hoochanlon@outlook.com>
Date: Sat, 1 Jul 2023 19:47:45 +0800
Subject: [PATCH] Update readme.md

---
 有趣的3/readme.md | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/有趣的3/readme.md b/有趣的3/readme.md
index efc6a04..c2b1bfb 100644
--- a/有趣的3/readme.md
+++ b/有趣的3/readme.md
@@ -4,6 +4,8 @@
 
 数学：
 
+简介
+
 * https://fanpusci.blog.caixin.com/archives/265869 财新网简介
 * https://blog.sciencenet.cn/blog-401820-1383173.html 一线数学教师应在三方面提升认识水平
 * http://jszy.whu.edu.cn/anfengwen/zh_CN/jxzy/225196/content/1024.htm 武汉大学教师个人主页
@@ -17,6 +19,8 @@
 * https://www.mathsisfun.com （[中文版](https://www.shuxuele.com)）
 * https://www.worksheetworks.com
 * https://www.purplemath.com
+* https://openstax.org
+* https://libretexts.org
 * https://corbettmaths.com
 * http://www.dzkbw.com/books/rjb/gaozhong-shuxue/
 * http://www.mathchina.com/bbs/