A:若②为脑部毛细血管,则曲线代表的是二氧化碳的含量变化
B:若②为肺泡处的毛细血管,则曲线代表的是氧气的含量变化
C:若②为胃部的毛细血管,则曲线可代表氧气的含量变化
D:若②为小肠绒毛内毛细血管,则曲线可代表营养物质的含量变化
阅读短文,下列问题
Everybody wants to be healthy. You know food is very important.There are many healthy foods. You can have more bananas, apples, oranges,tomatoes and lettuce because fruits and vegetables are good for you. But don't eat too much chocolate. It's not good for you. But don't eat too much chocolate. It's not good healthy food. Healthy food can make you grow and make you strong and happy. Remember there is a saying, “An apple a day keeps the doctor away.” Sports can also keep you healthy. Get up early and do some sports every day. Don't be lazy! You will be healthy and happy.