So far，China has built nearly 600，000 cultural centers in . （村庄）
I promised Li Ming I would keep the secret to . （我自己）
Jack enjoys and sunbathing with his friends. （游泳）
There are many online libraries where you can read books for ________, such as the national Online libraries Library of China and Shanghai Library. （免费的）
The app about how to learn Chinese is very popular ________ the foreigners.（在……当中）