Classen克拉森classn.等级；阶级；阶层；班级；课；[生]纲；<口>出色的风度v.分类classified discussion分类讨论class teaching reform课堂教学改革classromm instruction课堂教学class age-structure类年龄结构class of construction建筑等级class of permutations排列类class A amplification甲类放大class C amplificalion丙类放大class of contribution[电] 认担费用等级class teaching skills课堂教学技能