阅读表达。阅读下面短文并回答问题（请注意词数要求）。
On Sunday, April 22, people all over the world take time out to appreciate(珍惜)the earth that we all share. It’s Earth Day, a special day to learn about our planet(星球)and how to take care of it.
On Earth Day, some people listen to speeches about the environment. Others help clean up their offices or save water and electricity at home. Your parents may even decide to take a day off from driving their cars．
The idea for Earth Day came from a US Senator(参议员), who was worried about pollution and the health of plants and animals. And the idea quickly caught on(流行起来). In 1970, the first Earth Day was celebrated. More than 20 million people in cities all over the US took part in. Since then, Earth Day has been used to educate people about their role in taking care of our planet.
Now, Earth Day has become a global celebration. In 1990, 200 million people from 140 countries took part in clean-ups, tree planting and other environmental events on Earth Day.
When is Earth Day? (No more than 2 words)
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Who came up with the idea for Each Day? (No more than 3 words)
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How many people celebrated the flint Earth Day in 1970? (No more than 4 words)
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Is Earth Day popular around the world now? (No more than 3 words)
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What has Earth Day been used to educate people about their role? ( No more than 6 words).
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