Add: Closures
修改错字和排版
Update: Closures
Update
Update: 运算符函数
Merge pull request #26 from dabing1022/gh-pages

add 2-19 and 3-1
update the content
Update README.md
Update README.md
add content of ARC
Merge pull request #27 from TimothyYe/develop

add content of ARC
add arc content
bug fix
Merge pull request #29 from TimothyYe/gh-pages

勘误
update arc content
Update README.md
Update README.md
Update README.md
change the translation of initialization and deinitialization
Update README.md