Earth Hour started in Sydney o(1) March 31, 2007. M (2) than two million homes and Businesses turned off their lights for an hour. A year 1 (3) , in 2008, Earth Hour became the world's activity and was supported by _m( 4 )_ of people from thirty-five countries. In 2009, over two thousand cities in the world took part in it, and Earth Hour came to China. The purpose of the activity is to save energy and improve climate. Earth Hour has _b_(5)____ some new changes to our lives.
We may have different ways to spend the hour. For e(6)_______, we can go to school on foot or b (7) bike, plant more trees, use water more than once, never _l(8)____ the lights on when we are not at home. Try to make full use of paper by using b (9) sides. Earth Hour is a call for us to work together for a bright f (10) . It is also a message of hope and action. Everyone can make a difference. The improvement （改善）of our environment n (11) everyone's efforts（努力）. Come on! _J(12)_____ us in Earth Hour 2010!
