diff --git a/other/download.md b/other/download.md
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--- a/other/download.md
+++ b/other/download.md
@@ -5,39 +5,39 @@
 
 # 操作系统
 
-<a href="https://pan.baidu.com/s/1C-MgvslLKd1buwmebti6Qg"> <img src="s1650904.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/1Qm2G4rghPorQeH5J9fDHTg"> <img src="s4399937.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/1OoyVI90fK1Q9eixzH9jnpQ"> <img src="s4510534.jpg" width="150"/> </a>  <a href="https://pan.baidu.com/s/12mTkrpLsb7tz11cGn_KZ4w"> <img src="s3895413.jpg" width="150"/> </a> 
+<a href="https://pan.baidu.com/s/1C-MgvslLKd1buwmebti6Qg"> <img src="s1650904.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/1Qm2G4rghPorQeH5J9fDHTg"> <img src="s4399937.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/1OoyVI90fK1Q9eixzH9jnpQ"> <img src="s4510534.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/12mTkrpLsb7tz11cGn_KZ4w"> <img src="s3895413.jpg" width="150"/> </a> 
 
 # 算法
 
-<a href="https://pan.baidu.com/s/1Va1R66d13ynmita8nfkRPg"> <img src="s8938479.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/1HmGwXvTcHDrQnUAL1wWE3g"> <img src="s7038106.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/1SZGUbvKpKOomM-iYxe_GGw"> <img src="s2992671.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/10EoXyW33MnYJUX5YeD5pPg"> <img src="s28313721.jpg" width="150"/> </a>
+<a href="https://pan.baidu.com/s/1Va1R66d13ynmita8nfkRPg"> <img src="s8938479.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/1HmGwXvTcHDrQnUAL1wWE3g"> <img src="s7038106.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/1SZGUbvKpKOomM-iYxe_GGw"> <img src="s2992671.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/10EoXyW33MnYJUX5YeD5pPg"> <img src="s28313721.jpg" width="150"/> </a>
 
 # 设计模式
 
-<a href="https://pan.baidu.com/s/1JOO4M3c6EGB5xHz_-aGtDQ"> <img src="s2686916.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/1n41aEgGuRg9hQ-9iwOxc5A"> <img src="s1074361.jpg" width="150"/> </a>
+<a href="https://pan.baidu.com/s/1JOO4M3c6EGB5xHz_-aGtDQ"> <img src="s2686916.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/1n41aEgGuRg9hQ-9iwOxc5A"> <img src="s1074361.jpg" width="150"/> </a>
 
 # 数据库
 
-<a href="https://pan.baidu.com/s/1xhYsZUi2fugLf9jxSWA0pQ"> <img src="s2359163.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/1aXRWznphuiEc4XRXpM1qLA"> <img src="s4141593.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/182JK19-rvbISYAv4aLk7xg"> <img src="s5968156.jpg" width="150"/> </a>
+<a href="https://pan.baidu.com/s/1xhYsZUi2fugLf9jxSWA0pQ"> <img src="s2359163.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/1aXRWznphuiEc4XRXpM1qLA"> <img src="s4141593.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/182JK19-rvbISYAv4aLk7xg"> <img src="s5968156.jpg" width="150"/> </a>
 
 # Redis
 
-<a href="https://pan.baidu.com/s/1XovYaApdsVsd97pLCwAvpA"> <img src="s27297117.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/1bfbiPjoBEaNUs6qLWVEIJw"> <img src="s28296984.jpg" width="150"/> </a>
+<a href="https://pan.baidu.com/s/1XovYaApdsVsd97pLCwAvpA"> <img src="s27297117.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/1bfbiPjoBEaNUs6qLWVEIJw"> <img src="s28296984.jpg" width="150"/> </a>
 
 # Java
 
-<a href="https://pan.baidu.com/s/1iNBkY9ANUcmeSp4VjBGhRQ"> <img src="s27243455.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/1zdATX8Qs-RMk6DN7iqECYw"> <img src="s27458236.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/1LkPVPrT_3BYFkfxieBkeVw"> <img src="s7663093.jpg" width="150"/> </a>
+<a href="https://pan.baidu.com/s/1iNBkY9ANUcmeSp4VjBGhRQ"> <img src="s27243455.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/1zdATX8Qs-RMk6DN7iqECYw"> <img src="s27458236.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/1LkPVPrT_3BYFkfxieBkeVw"> <img src="s7663093.jpg" width="150"/> </a>
 
 # C++
 
-<a href="https://pan.baidu.com/s/1VhhqN7oVcrv0KhF32CXRLQ"> <img src="s27023182.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/1u3-QrdnkHo5ScUK84v7C5w"> <img src="s2996168.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/1K6xm3YlV53trCxyGR0j_gQ"> <img src="s4436543.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/10iFqDOHSveJC3VC7dl1vMw"> <img src="s1613283.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/1o-hgLJ4XvXAHeFhWAuuiFQ"> <img src="s4647091.jpg" width="150"/> </a> 
+<a href="https://pan.baidu.com/s/1VhhqN7oVcrv0KhF32CXRLQ"> <img src="s27023182.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/1u3-QrdnkHo5ScUK84v7C5w"> <img src="s2996168.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/1K6xm3YlV53trCxyGR0j_gQ"> <img src="s4436543.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/10iFqDOHSveJC3VC7dl1vMw"> <img src="s1613283.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/1o-hgLJ4XvXAHeFhWAuuiFQ"> <img src="s4647091.jpg" width="150"/> </a> 
 
 # 工具
 
-<a href="https://pan.baidu.com/s/1zYoS3lB1yCCT-So1YeoRuA"> <img src="s4245786.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/1ybA1qvjx4p844Pd8zDlx7Q"> <img src="s2794811.jpg" width="150"/> </a>
+<a href="https://pan.baidu.com/s/1zYoS3lB1yCCT-So1YeoRuA"> <img src="s4245786.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/1ybA1qvjx4p844Pd8zDlx7Q"> <img src="s2794811.jpg" width="150"/> </a>
 
 # 编码实践
 
-<a href="https://pan.baidu.com/s/1H1ilY54BISk7oDaKYpcrwA"> <img src="s1495029.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/1pWGwRRVxtpSmlsK7B1uU7Q"> <img src="s4157180.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/1HGHeahqtscz7iczhK7ps-Q"> <img src="s1671095.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/14uxNIdeXKLOnUJ6LMRndPg"> <img src="s10328621.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/17sIRZxCf_uJMZNnqAHEDkA"> <img src="s11194203.jpg" width="150"/> </a>  <a href="https://pan.baidu.com/s/1MaNeNsoqlTMn2uuT1QrsHQ"> <img src="s1086045.jpg" width="150"/> </a> <a href="https://pan.baidu.com/s/1s0vhcWxN_36PpZeJoOHrKA"> <img src="s4669554.jpg" width="150"/> </a>
+<a href="https://pan.baidu.com/s/1H1ilY54BISk7oDaKYpcrwA"> <img src="s1495029.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/1pWGwRRVxtpSmlsK7B1uU7Q"> <img src="s4157180.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/1HGHeahqtscz7iczhK7ps-Q"> <img src="s1671095.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/14uxNIdeXKLOnUJ6LMRndPg"> <img src="s10328621.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/17sIRZxCf_uJMZNnqAHEDkA"> <img src="s11194203.jpg" width="150"/> </a>  &nbsp;&nbsp; <a href="https://pan.baidu.com/s/1MaNeNsoqlTMn2uuT1QrsHQ"> <img src="s1086045.jpg" width="150"/> </a> &nbsp;&nbsp; <a href="https://pan.baidu.com/s/1s0vhcWxN_36PpZeJoOHrKA"> <img src="s4669554.jpg" width="150"/> </a>
 
 # 打包