阅读短文，根据短文内容，从短文后的五个选项中选出能填入空白处的最佳选项。选项中有一项为多余选项。（共8分，每小题2分）
April 22 is Earth Day. Everyone on earth should care about and protect the earth! The earth has warmed by about 1 °F over the past 100 years, but why and how? Well, scientists are not quite sure. Maybe the earth gets warmer and warmer on its own. __1__
First, greenhouse effect (效应) is a very important reason for the change of the earth. People give out too much energy into the air every year. It makes the earth warmer. __2__Sometimes it becomes too hot and sometimes too cold. Sometimes there is too much rain and sometimes too little. The change of the climate makes the earth warmer. In turn, the warmth of the earth changes the climate, too.
When the earth becomes warmer, there may be more rain and a rise in sea level. __3___ On a Pacific island, 100 people have to move to higher ground because the sea is rising. These people can no longer live on the coast. Before that, two islands without people went underwater in 1999. Scientists say that the seas can rise by nearly one metre by 2100.
People can affect the earth's air, land and water. As for us, we can do many things to protect the earth. __4___ We can tell more people about protecting the earth.

A.So it will affect the growth of plants, animals and people. B. But many scientists say that people are doing many things which make the earth warmer. C.For example, we can use fridges less. D. People in many cities turn off the lights for an hour on that day. E.Another important reason is climate change.