A Living a healthy lifestyle lies in forming the right eating habits.Here are some of the good habits you can develop when it comes to healthy eating. Drink plenty of water. You must drink at least 8 glasses of water a day. You may need even more water if you are in a hot environment or if you are exercising. Eat breakfast. Breakfast is the most important meal of the day. A recent study has shown that those who eat breakfast will consume an average of 100 calories less during the day than their colleagues ( 同事 ) who skipped breakfast. They will also be able to concentrate better. Don't skip lunch. If you do so, your blood sugar level will drop and your metabolism ( 新陈代谢 ) will slow down. When you get home you are starving and eat everything you can find. We all need to snack from time to time , but please choose your snacks carefully. In fact, it's a good idea to eat two healthy snacks besides your three main meals. Choose healthy snacks like fruits and vegetables , low fat yogurt , cottage cheese with apple sauce, and so on. Eat your fruits and vegetables. We should eat at least 5 servings of fruits and vegetables a day. Take a piece of fruit for a snack, add some banana and raisins to your favourite breakfast cereal ( 谷类食品 ), have a salad with lunch, and eat at least one vegetable at dinner each night. Do not eat your dinner too late. Try to eat dinner at least 3 hours before you go to bed. This will give your body a chance to digest most of the food before you rest for the next 8 hours. Plan dinner for the week ahead of time and make sure you have everything you need in the house so other family members can get a head start on dinner if you have a late meeting at the office.(回答21-24题) 21.How many good eating habits are mentioned in the passage?