根据短文内容和首字母提示，在下文空格处填入适当的词使短文完整。在标有题号的横线上，完整写出空缺处所填单词的正确形式。（每空一词）
Earth Hour started in Sydney on March 31，2007. O__
_1___ two million homes and businesses turned off their lights for an hour. A year 1ater，in 2008，Earth Hour became the w___
_2____ 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___
_3____ energy and improve climate(气候). Earth Hour has brought about some great c__
4__
to our lives.
We may have different ways of s__
_5___ the hour. For example, we can go to school on foot or b__
_6___ bike，plant more trees, use water more than once，never leave the lights o_
7___
when we are not at home. Try to make full use of paper by using b
8 sides.
Earth Hour is a call for us to work together for a bright f
9 . It is also a message of hope and action. Everyone can make a difference. It’s time for us to make our environment b_
10__. Come on! Join us in Earth Hour 2011!
