Time to Dance
Are you the kind of person who likes to move with music? It's a natural thing to do. Even little children start jumping up and down when they hear music.
Scientists say that animals dance, too_____小题1:______ . The "dances" of animals send messages to other animals. But when people dance, they express feelings about life and love, or about these very human experiences.
Dances are good for you in many ways. For one thing, dancing is good for you physically. It makes your heart work and makes you breathe fast. _____小题2:______. If you go dancing often, you can keep physically fit. You may feel very tired after dancing, but you’ll probably also feel relaxed and happy. This is another important point about dancing. It gives you a chance to express your feelings and feel better about yourself_____小题3:______, dancing helps those feelings go away.
_____小题4:______ Some dances are for couples and some are for groups. But all kinds of dances give you a chance to meet new people or to do something enjoyable with friends.
| A．But their dancing is different |
| B．And finally, it's a social activity |
| C．If people like dancing very much |
| D．If you are angry or upset about something |
E. It also makes you use your arms and your legs
，则
的值是 ．
是定义域为
上的增函数，
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，指出
单调区间，并证明你的结论．
