1、Wordsinthedialogues:Compulsory:义务的;必修的;被强制的compulsoryeducation义务教育compulsorycourse必修课compulsoryinsurance强制保险Somesubjects,suchasmathematics,physicsandEnglish,arecompulsoryforthestudentsinthisdepartment.有些课程,比如数学、物理和英语,本系学生都是必修的。Optional:adj.可选择的,随意的n.选修科目This is an optional