27+91=91+______．

Parents, doctors and teachers want to know how to help children keep healthy. Here are five rules to keep healthy.
Eat different food
If you eat different food, you can get the nutrients(营养) your body needs. You have to eat two kinds of fruits and three kinds of vegetables a day.
Drink water often
When you’re really thirsty, water is the No.1 choice. How much do kids need? If you are older than 12 years old, drink 3 cups a day.
Listen to your body
When you’re eating, notice how your body feels. Sometimes, people eat too much because they don’t notice when they need to stop eating. Eating too much can make you feel uncomfortable.
Limit(限制) screen time
What’s screen time? It’s the time you spend watching TV or using the computer. Try to spend at most two hours a day on the screen.
Be active(积极的)
What activities do you like best? Find ways to be active every day. You can write down lots of things to do, and then you can do them when your parents say it’s time to stop watching TV or playing computer games!

Rules to Keep Healthy
Eat different food	You can get小题1:       your body needs from different food.
Drink water often	It’s best to drink 小题2:   when you are really thirsty.
Listen to your body	You should notice when to 小题3:       . Don’t eat too much.
Limit screen time	You should spend no 小题4:   than two hours a day on the screen.
Be active	Don’t always watch TV or play computer games. Try to find ways to do your小题5:.activities.