$\frac{3}{8}$ 的分子扩大了3倍，要使分数的大小不变，分母应该增加____。

下列图例表示水库的是（   ）

    Today is Sunday. My Brother and I1at home. We2to take two boxes to the room.3box is big, but it's light(轻）. My brother's box is4, but heavy（重）. We put5on the table. We can see6clothes in the boxes, but my7aren't in them. I8find my socks. My Brother can9me to find them. They're10the bed. And my shoes are under it, too. I must look after (照看)my things. We put the11boxes away. The chair is12. My Brother and I can mend(修理)it. After that, we13basketball14the playground(操场). We are very happy. We like this15.