Fix bug in 6-1
Update origin
翻译：issue-13-1
Review 13-1
Merge pull request #199 from objccn/new/issue-13-1-nixzhu

翻译：issue-13-1
Publish 13-1
13-4 子类，翻译完毕
fix typo on issue-6-4
Review for 13-4
Merge pull request #200 from objccn/issue-13-4-Phenmod

13-4 子类，翻译完毕
Publish 13-4
Merge pull request #201 from qpwang/issue-6-4-typo

fix typo on issue-6-4
Fix typo
Fix space
commit