根据短文内容和所给中文提示，写出空白处各单词的正确形式。每空限填一词。
April 22^nd  is Earth Day, a special day to learn about our earth and how to take care of it. People all over the world take time out to      (保护）the earth.
On that day, some people listen to speeches about environment.       (其余的）help clean up their offices or save        (水）and electricity at home. Your parents may even        (决定）to take a day off from driving the cars.
The idea for Earth Day came from a US officer, who was        (担心）about pollution and the health of       (植物）and animals. And it        (迅速地）spread（推广）. In 1970, the first Earth Day was celebrated. More than 20        (百万）people in cities all over the U.S. took part in it.    (自从)then, Earth Day has been used to educated people about the role in taking care of our planet.
Now, Earth Day has        (变成）a global celebration.