enumDifficulty{beginng,easynormal,advance,expert}publicclassPaperFactory{publicstaticPaperProduce(Difficultydifficulty){}}publicclassPaper{DifficultyDifficulty;IEnumableQuestions}publicclassQuestion{DifficultyDifficulty;}Tobecontinued
内容全部来源于网络收集，如有侵权，请联系网站删除：QQ：24596024