Workers toast during a feast to greet the upcoming International Workers' Day, which falls on May 1, in southwest China's Chongqing, April 27, 2019. (Xinhua/Liu Chan)

Workers toast during a feast to greet the upcoming International Workers' Day, which falls on May 1, in southwest China's Chongqing, April 27, 2019. (Xinhua/Liu Chan)

Workers are seen during a feast to greet the upcoming International Workers' Day, which falls on May 1, in southwest China's Chongqing, April 27, 2019. (Xinhua/Liu Chan)

Workers enjoy a feast to greet the upcoming International Workers' Day, which falls on May 1, in southwest China's Chongqing, April 27, 2019. (Xinhua/Liu Chan)

Workers enjoy a feast to greet the upcoming International Workers' Day, which falls on May 1, in southwest China's Chongqing, April 27, 2019. (Xinhua/Liu Chan)