Earth Hour started in Sydney on March 31，2007. O___86___ two million homes and businesses turned off their lights for an hour. A year 1ater，in 2008，Earth Hour became the w____87____ activity and was supported by millions of people from thirty-five countries. In 2009，more than two thousand cities in the world take part in it，and Earth Hour came to China. The purpose of the activity is to s____88____ energy and improve climate. Earth Hour has brought about some new c__89__ to our lives.

　　We may have different ways of s___90___ the hour. For example, we can go to school on foot or b___91___ bike，plant more trees, use water more than once，never leave the lights o__92___ when we are not at home. Try to make full use of paper by using b 93 sides.

　　Earth Hour is a call for us to work together for a bright f 94 . It is also a message of hope and action. Everyone can make a difference. It’s time for us to make our environment b__95___. Come on! Join us in Earth Hour 里中国发生了巨大的