放寒假了，军军到乡下的外婆家玩。他在路边发现一条他从未见过的沟渠，听爸爸说是夏天的时候灌溉水稻用的。军军不禁产生疑问：这个沟渠有多深啊？为什么它要做成梯形的呢？你能回答军军的问题吗？

在下图中，上面的四个图形沿着虚线对折后会变成下面四个图形中的哪一个？画线连一连。    

阅读下面材料，在空白处按要求填入适当的单词或括号内单词的正确形式。每空1个单词。

    Dream House in California is not a house for only one or two children. It's a house for many ____(kid). It's a family. It's the future.

    Imagine____(live) in a hospital for many years because of illness. Imagine that one stays in a cold street____(连词) there is no other place to stay. These children need help. ____（代词）need Dream House.

    Many years ago, a little girl named Collin Rose____(decide) that when she grew up, she would offer a warm home____(介词) those sick and homeless children. When she grew up, she became____(冠词)  nurse and made her dream come true. In November 2003, Collin Rose set up Dream House.

    Collin Rose's efforts have____(encourage) many people to help sick and homeless children.

    "Every child should have a happy childhood. We may help make these children's lives____  (good) than before. Your small help may____(great) change their lives. No help is too small." Collin Rose said.