阅读理解。 1970 was World Conservation (保护) Year. The United Nations wanted everyone to know that the world was in danger. They hoped something could be done. Here is one example of the problem. At one time there were 1300 plants and flowers in Holland, but now only 866 are left. The others have been destroyed (毁坏) by modern man and his science. We are changing the earth, the air and the water and everything around us. We can't live without these things. If things go on like this, we shall destroy ourselves. What will happen in the future? Perhaps it is more important to ask 'What must we do?' More and more young people have known this. Many of them are helping to save our world. For example, they plant trees. In a small town in the USA a large group of girls cleaned the banks of 11 kilometres of their river. Young people may hear about conservation through a song called 'No one's going to change our world'. It was made by Cliff Richard and other singers. The money from it will help to conserve tigers, elephants and pandas on the earth. 1.There're not so many plants, trees and flowers in Holland now because _____. [     ] A. Holland doesn't need so many plants, trees or flowers B. people in Holland need more land to live on C. there has been little conservation there D. the weather there isn't fit for farming 2.The song called  'No one's going to change our world' encourages people to _____ . [     ] A. grow more trees and flowers B. protect our environment and save our world C. make our life easier and more comfortable D. save plants and animals on the earth 3.If we go on changing the earth and everything around us, some day _____. [     ] A. there will be no air on the earth B. there will be no food for the people C. we will have to work even harder D. we will destroy ourselves 4. The word 'conserve' in the last sentence means '_____'. [     ] A. help B. save C. change D. destroy 5.The writer warns us _____. [     ] A. not to be modern man and develop science B. not to change the animal and plant's life C. that our world is in danger D. that people all over the world are in danger