摘要

<正>It’s spring and lots of busy bird parents nesting,laying eggs and taking care of baby birds.Next comes baby birds learning to fly.How do birds fly?Why doesn’t gravity1 pull them down to the earth?And why can they fly and we can’t?Here’s what we learned.现在是春天,许多忙碌的鸟爸爸、鸟妈妈正在筑巢、下蛋和照顾雏鸟。接下来雏鸟就要学习飞翔了。鸟是怎么飞翔的呢?为什么重力没有把它们拉到地上?为什么它们能飞而我们人类不能呢?下面是我们了解到的内容: