海狸观察 一个人 xkcd Randall Munroe https://xkcd.com/about/ https://xkcd.com/ CC-BY-NC-2.5 https://www.explainxkcd.com CC-BY-SA-3.0 We will try to fix translation errors. Index xkcd comic index 中文xkcd漫画索引 what if 中文索引