我们在一个供应正宗意大利菜的餐厅吃了饭。

We ate at a restaurant serving ___authentic Italian food.

我也很怀念正宗的泰国文化，它已被美国文化和欧洲文化微妙而逐渐地取代。

I am also nostalgic for ___authentic Thai culture which has subtly and gradually been replaced by American and European culture.

博物馆展出了一封由著名历史人物亲笔书写的真实信件。

The museum displayed an ___authentic letter written by a famous historical figure.