Update 23.0.md
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Update 07.0.md
Merge pull request #164 from Frederick-S/master

增强英文版第七章的可读性
update chapter 30
update chapter 29
Update Readme.md
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Merge remote-tracking branch 'upstream/master'
fix bug for using '\' failing pdf generation
Merge pull request #166 from adrian-wang/master

fix bug for using '\' failing pdf generation
remove unnecessary lines in build/makefile
Merge remote-tracking branch 'upstream/master'
Update chapter01.rb

替换array为字符串

修复一些不好理解的变量名
Merge pull request #168 from jjyr/master

Update chapter01.rb