Cooperative activity is essential to effective community work.
要把社区工作做好，协作活动是必不可少的。
It is essential that we present a united front.
至关重要的是我们要表现得团结一致。
Good posture is essential when working at the computer.
用电脑工作时良好的姿势极其重要。
The agreement is essential to spurring economic growth around the world.
这项协议对于促进世界经济的增长是至关重要的。
A degree is an essential prerequisite for employment at this level.
学位是做这级工作必备的先决条件。