急性牙髓炎的主要病理变化是 A．血管扩张、中性粒细胞浸润 B．血浆渗出、淋巴细胞浸润

What will you do if weight keeps going up? Here are ideas to help you stay healthy:
Don’t sit around
Stay active. Try to exercise 30 to 60 minutes every day. Your exercise doesn’t have to be hard. Start small. Take the stairs instead of the elevator(电梯). Walk or ride a bike to places such as school or a friend’s house. Help your mum with housework, such as cleaning windows or the bathroom. It all burns fat. Make changes from time to time so you don’t get bored: Try running, biking, skating. There are many choices. Don’t spend long hours watching TV or playing video games. Even reading a book burns more fat.
Eat healthy
Truly different kinds of food and get enough fruits and vegetables each day. Drink water and low fat milk instead of soft drinks like Cola. Stay away from fast food. Eat when you are hungry, not when you are bored or because you can’t think of anything else to. Don’t eat meals or snacks while watching TV because you’ll probably end up eating more than you need. Some worry so much about their weight that they don’t eat breakfast. This is a bad idea. Teenagers need enough food. If not, you won’t get the nutrients you need to grow normally.
Don’t rush to go on a diet
Even if you are a little heavier than your fiends, you still may be normal. Remember to talk to doctors and your parents before you decide to lose weight.

Don’t	Do
Don’t sit around	Stay 小题1:_____Try to exercise 30 to 60 minutes every day
Don’t spend long hours小题2:______TV or playing video games	Even reading a book burns more fat
Don’t eat fast food	Try 小题3:_____ kinds of food and get enough fruits and vegetables each day
Don’t eat when you are bored or because you can’t think of anything else to do.	Eat when you are小题4: ______
Don’t rush to go on a 小题5:______	Talk to doctors and your parents before you decide to lose weight