英语以过去式写地球一小时小作文

Earth Hour, an annual international event held on the last Saturday of March, asks people to turn off their lights from 8.30 to 9.30 pm of the local time. Its purpose is to raise people’s awareness of the environmental protection and the climate change. Earth Hour first began in Sydney in 2007 and after that, it spread around the world at an amazing speed. This year, more than 4,000 cities from 90 countries and about one billion people from the world have joined Earth Hour. Though it is a simple mass event, people are contributing their own way to saving our planet and one hour’s dark means a bright future.