一、例句

The book is at its best when it treats Martin Luther King, Jr. and Malcolm X pragmatically, as two leaders with different inclinations and separate power bases but sometimes convergent interests. (The Economist) 

二、句子解析

参考译文：这本书最出色的地方就是它以务实的态度对待马丁·路德·金和马尔科姆·X，把他们当作两个有着不同倾向和各自权力基础，但有时利益趋同的领导者。

这句话选自最新一期《经济学人》Books and arts 版块的 The ballad of Malcolm and Martin 一文。这篇书评介绍了一本采用平行写法、同时为两位民权运动家——马丁·路德·金和马尔科姆·X 立传的新书。

如果我们自己来写这句话，可能会这样写：

What the book does the best is that it treats Martin Luther King, Jr. and Malcolm X pragmatically, as two leaders with different inclinations and separate power bases but sometimes convergent interests.

所以，当我们想表达“X 最出色的地方就是 Y”时，就可以使用“X is at its/his/her best when it/he/she does Y.”这个新的高频、地道句式。

再比如，《纽约时报》中也有这样的句子：

NASA is at its best when it has a short time to figure out things.

His book is at its best when it sticks to the Bronx and the fires there.

三、句式临摹

临摹句子：

The book is at its best when it treats them pragmatically, as two leaders with different inclinations and separate power bases but sometimes convergent interests.

提炼句式：

X is at its/his/her best when it/he/she does Y.（X 是单数）

X are at their best when they do Y.（X 是复数）

注意：

X 是名词，决定了后面物主代词的形式。

造句示范：

a）场景：这名巴西柔术女运动员最厉害的地方在于越挫越勇。

The female jiu-jitsuka is at her best when she is faced with formidable challengers.

注意：female, her, she 的一致性。

b) 场景：试卷越难越能体现出学霸的水平。

Top students are at their best when they take a hard test.

四、作业

参考第三部分的句式造句，造句时尽量用中文写出具体的语境。