adj.强制性的，(按法律、规定等)必须的，强制的，习惯性的，随大溜的，赶时髦的

Chinese class is an obligatory course.
语文是一门必修课。
Eric's lips curved up in the obligatory smile, acknowledging the compliment.
埃里克习惯性地微笑了一下，以示称赞。
Mary was wearing the obligatory sweater and pearl necklace.
玛丽穿着那件经常穿的毛衣，戴着那串惯常戴的珍珠项链。
Attendance at the meeting is obligatory for all team members.
参加会议是所有团队成员必须的。
Wearing a helmet while riding a motorcycle is obligatory by law.
骑摩托车时戴头盔是法律规定的义务。
It is obligatory for students to complete a certain number of community service hours each year.
学生每年必须完成一定数量的社区服务小时。
Providing a valid ID is obligatory when opening a bank account.
开立银行账户时，出示有效身份证件是必需的。
The company has made it obligatory for employees to attend a yearly training session on workplace safety.
公司规定员工必须参加一年一度的工作场所安全培训。
Filing taxes annually is an obligatory task for citizens over a certain income threshold.
年收入超过一定门槛的公民每年报税是一项强制性任务。
For this course, submitting a final project is obligatory to pass.
在这门课程中，提交期末项目是通过的必要条件。
All guests are subject to a security check, which is obligatory for entry into the venue.
所有来宾都必须接受安全检查，这是进入场馆的必经程序。
Learning the national anthem is obligatory in many schools as part of patriotic education.
在许多学校，学习国歌作为爱国主义教育的一部分是强制性的。
It's obligatory for medical professionals to maintain patient confidentiality.
保持病人隐私对医疗专业人员来说是必须遵守的。