adj.强制的;势在必行的;义务的
Attendance at evening prayers is not compulsory. 参加晚祷并非硬性规定。
I think it is compulsory. 我认为这是非做不可的。
The car insurance is compulsory. 这项汽车保险是强制性的。
Building model stars is a compulsory task. 建立恒星模型是一项势在必行的任务。
Is English a compulsory subject? 英语是必修科目吗?
Is military service compulsory in your country? 你们国家实行义务兵役制吗?