,栏目导航,A,B,A,B,C,B,south,cheap,big trees,summer,friendly,A,B,C,A,C,B,C,B,A,C,The Earth provides a lot of energy for us. We should protect it.,We should put rubbish into the dustbin.,There are many animals and plants living on the land.,If you take a photo of the Earth, you will find that it is covered by three quartersof water.,We must take action to protect the Earth at once.,
