Perl6版pdf、[Learning.Perl.Student.Workbook(2nd,2012.01)].brian.d.foy.文字版（此为比书后练习难度更大更综合的练习集，为英文版） 另附部分章节的正确答案。均测试。-Perl6 edition pdf, [Learning.Perl.Student.Workbook (2nd, 2012.01)]. Brian.d.foy. Text version (this is more difficult than the back of