About 20 Chinese cities joined a worldwide relay on Saturday night to switch off lights of major buildings for one hour to highlight concerns about climate change while calling for actions.

上周六晚上全中国有二十多个城市参加了全球性的应对气候变化，城市主要建筑物熄灯一小时的活动。

youdao

Please switch the lights off as you leave.

你离开的时候请把灯关了。

《牛津词典》

Turn the light off as you go out.; Please switch off the lights when you leave.

出门时请随手关灯。

《新英汉大辞典》

"In hotels, switch off lights and re-use linens, " advises Chan.

BBC: Sustainable travel in Malaysia

The Kremlin due to switch off its lights at 16:30 GMT along with 90 other landmark buildings in Moscow.

BBC: Sydney dims down for Earth Hour climate change protest

It encourages cities and individuals to switch off non-essential lights for an hour at 20:30 local time.

BBC: Sydney dims down for Earth Hour climate change protest