题目内容：

Each summer，you hear news that some sports players are sent to hospitals because it is too hot. Our bodies can't be outside in the sun for a long time. So in hot summers，be careful about playing sports outside.

Firstly，to play sports safely in hot weather，you must drink water. Sports drinks are great for athletes，but they have so much sugar that they'll dehydrate（使脱水）you more. However，drinking a few bottles of sports drinks will be good for you.

Secondly，be sure to take enough breaks to let your body rest. If your coach doesn't let you take enough breaks in the heat，don't wait until you feel uncomfortable. Just be honest with your coach when you need breaks.

Thirdly，when you have a break，don't sit in the sun. With the sun beating down on you，you'll only heat up and sweat（冒汗）more. Take a seat under a tree，or even better，go indoors for a little while. Cooling yourself down can help you stay active longer.

Fourthly，remember that the earlier in the day you start your exercise，the cooler it will be. If you can start practice before the sun comes up，you have a few good hours to practise in the cool hours of the morning. Also，the earlier you practise，the earlier you can finish the exercise. If you need more practice time，come back to the field later in the evening，when the sun is setting.

Last but not least，you should watch what you eat. Eat food which is high in water，starch（淀粉）and carbonhydrate（糖类），but be sure to get a good balance in your diet.

As long as you pay attention to the above，playing sports safely in the heat isn't a difficult thing.

1.How many pieces of advice are mentioned in the passage?

A．Three            B．Four            C．Five              D．Six

2.From Paragraph 5 we know        ．

A．we'd better start our exercise early 

B．it is not wise to have practice after aunset

C．we have a long time to practise after sunrise 

D．it doesn't matter whether you practise early or late

3.Which of the following is true according to the passage?

A．Sports drinks are good for you with no harm．

B．You need to tell your coach when you feel tired．

C．Sitting under a tree is better than staying indoors．

D．Eating lots of sugar is necessary for sports safely．

4.The passage mainly tells us about        ．

A．eating habits in hot summers 

B．drinking more water in the heat

C．sports safely in hot weather

D．taking exercise in different periods