Every year on April 22, People all over the world celebrate Earth Day. It is a time to work to keep our earth clean. People plan projects to clean up the land, air and water. U.S. Senator Gaylord Nelson first thought of the idea for Earth Day in 1962 when he saw polluted rivers and cities with smoke. He needed to get support from Americans to clean up the earth. Finally, on April 22, 1970, 20 million Americans celebrated the first Earth Day! Now many countries around the world celebrate it, and you can, too. How can you celebrate Earth Day? Here are a few ideas: Join a clean-up project------Clean up your street or a favorite beach. Save energy------Turn off the lights when you leave a room, and use public transportation. Use less water. Reduce(减少)/ Reuse/ Recycle ------ Practice the three Rs: First, reduce how much you use. Then reuse or recycle what you can. You can make a difference on Earth Day and every day! 小题1:When was the first Earth Day? A．On April 22, 1970. B．On April 22, 1962. C．On April 22, 1971. D．On April 22 every year. 小题2:People celebrate World Earth Day every year to  _____ A．have great fun B．keep our earth clean C．get to know each other D．get support 小题3:How do people around the world celebrate Earth Day? A．By using more cars. B．By helping clean up the land, air and water. C．By polluting rivers and cities. D．By taking fewer buses. 小题4:Which of the following sentences is NOT true? A．Americans celebrated the first Earth Day. B．Three Rs mean reduce, reuse and recycle. C．Now about 20 million people celebrate the Earth Day. D．People celebrate Earth Day by helping to do some public cleaning.