Earth Hour is an annual event, asking you to switch off all your lights for one hour in positive change for our planet. It is organized by the World Wide Fund for Nature and it's a big event usually at the end of March every year. , which means switching off all lights everywhere at the same time for one hour.

Earth Hour started in Australia in 2007, when 

2.2 million people in Sydney turned off all unnecessary lights for an hour. , and many countries around the world have taken part.

It's true that switching off the lights for just one hour saves only a little power. . Joining in Earth Hour makes people think about the problem of climate change and how to protect nature so that people can enjoy healthy and sustainable lives. Besides, many people acting together pushes governments and companies to consider green issues when making big decisions.

. The number 60 is for the 60 minutes of Earth Hour, and the plus invites people to keep on taking action even after Earth Hour is finished. In fact, people joining in Earth Hour say that taking part in it inspires them to do more for the environment. The climate activist Greta Thunberg says, "Earth Hour is every hour of every day."

Why is it in March? At the end of March in the northern and southern hemispheres (半球), the days and the nights are almost of the same length. , so it is dark in the evening in each country for the Earth Hour switch-off.

A. But this is only the beginning

B. The logo of Earth Hour is "60+"

C. On this evening, people "go dark"

D. There are many events people can join in

E. Since then it has grown into an international event

F. The idea is to raise the awareness of environmental issues

G. At this time, the sunset time is similar in both hemispheres