根据 https://download.csdn.net/download/xueshengyuan/6642383?spm=1001.2101.3001.6650.1&utm_medium=distribute.pc_relevant.none-task-download-2%7Edefault%7EBlogCommendFromBaidu%7EPaidSort-1-6642383-blog-108825377.235%5Ev43%5Epc_blog_bottom_relevance_base6&depth_1-utm_source=distribute.pc_relevant.none-task-download-2%7Edefault%7EBlogCommendFromBaidu%7EPaidSort-1-6642383-blog-108825377.235%5Ev43%5Epc_blog_bottom_relevance_base6&utm_relevant_index=2 操作，然后加上了IP，文件长这样：

（由于滥用标题行导致发不出去，带'#'的行没放）

127.0.0.1	localhost.sangfor.com.cn

174.36.30.67 dropbox.com
174.36.30.71 www.dropbox.com
75.101.129.115 dl.dropbox.com
75.101.159.151 dl.web.dropbox.com
174.36.30.67 forums.dropbox.com

所以为啥还是不能访问