On July 21, local time, US President Trump urged Americans to "wear a mask" at a press conference, stating that "No matter whether you like wearing a mask or not, it is always useful." A reporter asked Trump why he didn't wear a mask when he urged others to wear it. After listening to Trump, he took the mouth mask from his pocket and said that he would wear it when necessary. (Editor Zeng Chen)

Editor in charge: [Li Ji]