1、essential

绝对必要的;必不可少的;基本的

It was absolutely essential to separate crops from the areas that animals used as pasture.

将庄稼和放牧区分开绝对必要。

As they must also sprint over short distances, speed is essential.

由于他们也必须进行短跑，因此速度至关重要。

基本的;本质的；根本的

Most authorities agree that play is an essential part of a child's development.

大多数权威人士都同意，玩耍在孩子成长过程中起着非常重要的作用。

In this trial two essential elements must be proven: motive and opportunity.

在这次审讯中，必须证明两个基本因素：动机和时机。

（某学科的）基础，基本知识

the essentials of everyday life, such as eating and exercise.

饮食、锻炼等日常生活的要素

This has stripped the contest down to its essentials.

这就使比赛精简到最基本的环节。

2、progress

进步；进展

The medical community continues to make progress in the fight against cancer.

医学界在抗癌的斗争中不断取得进步。

The two sides made little if any progress towards agreement.

双方在达成协议方面的进展甚微。

继续进行；逐步发展

As the evening progressed, sadness turned to rage.

随着夜幕逐渐降临，悲伤变成了愤怒。

Life was hard, and it became harder as the war progressed.

那时候生活很艰难，并且随着战争的持续愈发艰难了。