Cooperative activity is essential to effective community work.

　　要把社區(qū)工作做好，協(xié)作活動是必不可少的。

　　It is essential that we present a united front.

　　至關(guān)重要的是我們要表現(xiàn)得團(tuán)結(jié)一致。

　　Good posture is essential when working at the computer.

　　用電腦工作時良好的姿勢極其重要。

　　The agreement is essential to spurring economic growth around the world.

　　這項(xiàng)協(xié)議對于促進(jìn)世界經(jīng)濟(jì)的增長是至關(guān)重要的。

　　A degree is an essential prerequisite for employment at this level.

　　學(xué)位是做這級工作必備的先決條件。