This is the 7166th most frequent Portuguese word.
lanzhou
"Lanzhou" is not a Portuguese word; it refers to a city in China.
In this sentence, 'Lanzhou' is used as a proper noun referring to a specific geographic location, namely a city.
Lanzhou é uma cidade localizada na China.
Lanzhou is a city located in China.
Here, 'Lanzhou' is utilized again as a proper noun, signifying that the name of the city is a subject of discussion or study.
Eu li sobre Lanzhou em um livro de história.
I read about Lanzhou in a history book.
In this case, 'Lanzhou' denotes the city as the place where the described culture is found.