这部小说例证了19世纪的社会问题。

The novel ___exemplifies the social issues of the 19th century.

她的故事例证了移民在新国家的挣扎。

Her story ___exemplifies the struggles of immigrants in a new country.

这个实验例证了能量守恒原理。

This experiment ___exemplifies the principle of conservation of energy.