根据图片写出2道乘法算式和2道除法算式

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完形填空
      This is my desk, and 1 books are on it. One is yellow and the other(另外的) is blue. You can see a 2 on the desk, too. The clock is red. My pencil case is3 the desk, too. A  pen, an eraser  and a ruler4in it. The pen is black. The5 is yellow, and the ruler is white.
    6 is my pencil? Well, it's under the desk. A baseball is under the7too. But the baseball isn't 8. It's my brother's. Is my computer under the desk, too? No，9isn't. Where is it? I can't10it in the room.

下面的年份中，(    ) 是闰年。

由以下粒子结构示意图（如图所示）得出的结论中，错误的是（   ）

下列各式计算结果为a⁷的是（   ）