来自essence, 本质。

1. Jordan promised to trim the city budget without cutting essential services.

乔丹承诺在不减少基本服务的前提下，缩减市政预算。

2. Party membership was an essential prerequisite of a successful career.

成为党员是事业有成必不可少的先决条件。

3. "Aromatherapy oils" are not pure essential oils but dilutions.

“香薰精油”并非纯精油，而是经过稀释的。

4. It is essential to feel at ease with your therapist.

在治疗师面前放松下来是很重要的。

5. Polyunsaturated oils are essential for health. Excess is harmful, however.

多不饱和油对健康很重要。但是，食用过量就会有害。