vital

These matters are vital to national defense.这些事情对国防至关重要。

He played a vital [=key] role in guiding the project.他在项目指导方面起了关键作用。

The sciences are a vital part of the school curriculum.理科课程是学校课程必不可少的组成部分。

It is vital that you follow all safety procedures. = It is of vital importance that you follow all safety procedures.遵守所有的安全规程极其重要。

your heart, lungs, and other vital organs你的心、肺和其他重要器官

Exercise keeps her young and vital.锻炼使她始终焕发出青春活力。

Their music still seems fresh and vital after all these years.这么多年过去了，他们的音乐似乎依然清新而有活力。