你能将两道一步计算的算式合并成一道两步计算的算式吗？试试看．

7×1×3＝21；____；____；____

已知函数 $y=(m^2+m)x^{m^2-2m+2}$ ．

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    If you often have a cold, headache or backache, there is something wrong with your health. Eating healthy food 1good for our health.
    Tofu（豆腐）, milk, vegetables are healthy for us. Tofu is a kind of traditional（传统的）2food. We often 3 it in China. Now more and more people 4 other countries think tofu is good for health, 5. They also like eating it. Milk is 6  kind of health food. Every day you should  7  one or two glasses of milk.
    It can 8 us strong.
    Vegetables are very important. You should 9 them. There are vitamin(维他命) A, B, C, D , E and so on in them.
    As we know, it's important10 a balanced diet(均衡饮食). We must have the right kinds of food. We should also eat some pork, chicken and beef. We should eat more fruit and vegetables but less meat.

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