"Singing Chinese songs was the happiest part of the day during the two months that we studied at home," four students from a German high school choir wrote in a letter to Peng Liyuan, the wife of President Xi Jinping.

The letter, written in Chinese, was in reply to a letter from Peng on Feb 9 to the students and teachers at Burg Gymnasium, encouraging them to contribute to promoting the friendship of the Chinese and German peoples.

The students said they have read Peng's letter many times and are very excited.

"We feel so proud after knowing that you even watched our video," they wrote in the letter, referring to a video clip in which students sang a Chinese song, After the Pandemic.

Simone Reuen, the principal of Burg Gymnasium, said in her letter to Peng that she was extremely happy that the school had received so much recognition.

"Your letter is a great commendation, recognition and encouragement to our school and the work of our school's Chinese choir," Reuen wrote.

Reuen said that she believed that their songs have played a slight but very important role in the exchanges and mutual learning between people in Germany and China.

She said she was proud of the students for shortening the distances between the two peoples.

The students and teachers at the school asked the Chinese embassy in Germany to forward the reply letters to Peng, together with works of calligraphy and other handicrafts made by the students.

Burg Gymnasium, located in Essen, is one of the 12 oldest public schools in Germany. It has been offering Chinese language courses since 1994, and has organized several visits to China for exchanges in recent years.

In March 2014, Peng visited the school and joined a Chinese class there during Xi's state visit to Germany. In October 2016, Peng met with the teachers and students of the school in Beijing.