注意：①短文须包括所有内容提示，可适当发挥；

②词数：100左右

1）饮食；2）睡眠；3）体育锻炼。

民族团结是各族人民的生命线。各民族同胞要手足相亲、守望相助，共同维护民族团结、国家统一。这是因为（　　）

根据材料内容，选择正确答案。

    It is nice to hike with kids, but you must know something about hiking if you want to take a happy, relaxing trip.

    Start early, know what to do in a heavy rain and carry sunglasses. Take snacks, toilet paper and a bag with you. Take a whistle(口哨) for kids. You may use it if children run away.

    Find a partner. Kids are naturally competitive, and you can use this to your hike. They will try to do better than each other when they go hiking. They also will keep each other interested in something new.

    Do something easy. It's good to play easy games. You can say "Does anybody see anything red that matches my shirt?" Kids will be easy and happy to answer this kind of questions.

    If you aren't excited, they won't be either. When your kids find something they are interested in, you must show your interest in it, too.

等式两边都除以同一个不是0的数，所得的结果仍然是等式．