先通读下面的短文，掌握其大意，然后在每小题所给的A、B、C、D四个选项中，选出可以填入空白处的最佳选项。
No one likes being sick. From the runny nose and sore throat of a cold to the fever and the flu, being sick can
1 slow you down. Since there isn't a good way to deal with either the cold or flu, you just have to get 2
the terrible days. But with proper care, you won't be sicker and you can be better sooner rather than later.
Stay away from work or study.Your 3 is the best place for you now. Going out and having a normal day will 4 make you sicker. It also exposes (暴露) those around you to illness. Stay home and take care of yourself so that you can go out again soon.
5 as much as you need. Sleeping can be one of the most necessary steps in allowing your body to get better. When a 6 attacks(攻击) your body, it needs as much energy as it can to fight it off. Sleep helps give you that energy.
Avoid doing sports. Even if you do it every day and find it gives you increased energy, working out when you're
7 doesn't give you that energy. It makes you even worse.
Wash your hands frequently (频繁地).This will help prevent you from getting 8 germs(细菌) and possibly getting sicker. It's also going to help you get rid of the germs that have collected on your 9. Wash your hands with hot water and soap 10 at least 20 seconds.
定义域是（ ）
