任务一:请你根据上面的三段描述,判断句子正(T)误(F),将答案写在题前括号内。
()1. Dudu climbed the mountain with his friends.
()2. Dudu is heavier than his dad.
()3. Dudu's brother is shorter than Dudu.
()4. They got to the top at 10 a. m.
()5. They were all tired but happy.

任务一:1. F 2. F 3. T 4. T 5. T

任务二:Think and answer.(想一想,回答问题。)
1. Who is thinner than Dudu's dad?

2. Who is the tallest in Dudu's family?

任务二:1. Dudu's mum.
2. Dudu's dad.

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小小科学家：影子变变变
同学们，你们知道吗？影子的长短会随着太阳的位置发生变化。让我们一起做个有趣的小实验，观察影子的秘密吧！
（图2）
我的实验记录
| 位置 | 影子长度 |
| ---- | -------- |
| （台灯从上照射的实验图，标注图1） | cm |
| （手电筒从侧照射的实验图） | cm |
我的发现：
When the light comes from the top, the shadow is (shorter/longer).
When the light comes from the side, the shadow is (shorter/longer).
So, the (lower/higher) the sun is, the longer the shadow is.
挑战任务：
想一想，一天当中，你的影子在什么时候最长？在什么时候最短？
My shadow is the (longest/shortest) in the morning and evening.
My shadow is the (longest/shortest) at noon.
（图3）

shorter, longer, lower, longest, shortest