形势的英文：
circumstances
situation
terrain

参考例句：

A potentially catastrophic situation.
可能引发严重灾难的形势。

He summed up the situation in three short paragraphs.
他把形势归纳为三小段。

An awkward or perplexing situation;a predicament.
困境令人难堪或困窘的形势；窘境。

I then made some groundless remarks, assessing the situation over-optimistically
然后，我毫无依据地对形势作出了过于乐观的分析。

Haig served his country well and honorably in its extremity
黑格在国家处于走投无路的形势下出色地，体面地为国家尽了职责。

An opening in chess in which a minor piece, or pieces, usually a pawn, is offered in exchange for a favorable position.
第一着棋，起手着法国际象棋开局时自愿让出一个或几个小棋子（通常为兵）以交换较有利的形势。

The situations allow of no excuse.
形势刻不容缓。

The prospects are gloomy
形势不稳

mercurial situation
易变的形势

Bright prospects
形势甚好

circumstances是什么意思：
n. 条件，境遇，命运

It depends on circumstances.
这要视情况而定。

Man is not the creature of circumstances; circumstances are the creature of man
并非时势造人,而是人造时势

A particular detail or circumstance.
详情详尽的细节或情形

situation是什么意思：
n. 情况；状况；局面；处境，境遇；位置；地点

appreciation [of situation]
判断〔局势〕

mercurial situation
易变的形势

a survey of the situation, subject
对情况、 问题的概括论述

terrain是什么意思：
n.[C,U]
地带，地域，地形，领域

And throughout this terrain, Gardner is an able tour guide.
而在这一领域，加德纳是一位能干的“导游”。

Indecisive Boundaries running through mountainous terrain.
高山岩层上不明确的边界

It was obvious that David knew the terrain very well.
很明显，大卫对这里的地形十分熟悉。