Firefighters take part in an emergency drill at the Potala Palace in Lhasa, Southwest China’s Tibet autonomous region, April 2, 2018.[Photo/Xinhua]

Firefighters patrol at the Potala Palace in Lhasa, Southwest China’s Tibet autonomous region, April 2, 2018. [Photo/Xinhua]

Firefighters check fire extinguishers during an emergency drill at the Potala Palace in Lhasa, Southwest China’s Tibet autonomous region, April 2, 2018.[Photo/Xinhua]

Firefighters take part in an emergency drill at the Potala Palace in Lhasa, Southwest China’s Tibet autonomous region, April 2, 2018. [Photo/Xinhua]