①如果货币流通速度保持不变，货币的供应量应增加2500亿元

②如果货币流通速度保持不变，货币的供应量应减少2500亿元

③如果货币的供应量保持不变，货币的流通速度要降低50％

④如果货币的供应量保持不变，货币的流通速度要提高50％

    It's very important(重要的) for us to be healthy. Now I'll tell you how I can be healthy. I often eat fruit and vegetables. I don't like to eat hamburgers. They are not good for my health. I have a balanced diet. Many foods are important, such as rice, meat, eggs, vegetables and fruit. I like to eat apples. As the saying(谚语) says, “An apple a day keeps the doctor away.” And I also like doing sports. I like running in the morning. I play basketball in the afternoon with my friends. And sometimes I play ping­pong with my family at the gym on Saturdays. I think I'm healthy and strong. What about you?