A student displays a stamp that she created at a primary school in Qinhuangdao, Hebei Province on October 8, 2018. Students at the school designed stamps to mark the World Post Day, which is celebrated annually on October 9. [Photo: VCG]

Students showcase their creative stamps at a primary school in Handan, Hebei Province on October 8, 2018. The activity is to mark the World Post Day, which is celebrated annually on October 9. [Photo: VCG]

A student displays a stamp that he created at a primary school in Qinhuangdao, Hebei Province on October 8, 2018. Students at the school designed stamps to mark the World Post Day, which is celebrated annually on October 9. [Photo: VCG]

A student does a drawing of a stamp at a primary school in Handan, Hebei Province on October 8, 2018. Students at the school designed stamps to mark the World Post Day, which is celebrated annually on October 9. [Photo: VCG]