有必要的英语怎么说

有必要的英语可以说为"necessary"或"essential"，也可以用"required"或"mandatory"来表示。

1. It is necessary to wear a helmet when riding a motorcycle. (骑摩托车时戴头盔是必要的。)

2. It is essential to have a good night's sleep before an important exam. (重要考试前有一个良好的夜间睡眠是必要的。)

3. It is required to submit the application before the deadline. (在截止日期之前提交申请是必须的。)

4. Attendance is mandatory for all employees at the safety training session. (所有员工在安全培训课程上的出勤是强制性的。)