what is Earth Day?when is Earth Day?

what is Earth Day?when is Earth Day? What is the displacement of Earth after a time interval of 365 1/4 day What is the displacement of Earth after a time interval of 365 1/4 day 是什么意思? world earth day aims at what What on earth is rap? what is happiness on earth? what is thanksgiving day? What day is it What day is it what day is today? What is Boxing Day What is the biggest animal on earth? what on earth is it anyway What is a Friend of the Earth? what is the shape of the earth? 英语阅读题 Where does the wind come from?What makes the wind move all the time?Scientists tell us that it is the sun that makes it move,and makes it blow.When the sun shines on the earth,it makes the earth hot.Then the earth makes the air hot.Wh Earth Day is celebrated every year on April 22 What day is it today