established rule or practice established rules and regulations set pattern
established rule or practice
established rules and regulations
set pattern
定角用英文怎么说
定解条件用英文怎么说
定解问题用英文怎么说
定言令式用英文怎么说
定计用英文怎么说
英语词典收录了最新的汉英词典和英汉词典,总共有200多万个词条,词库仍在不断更新中。