For the smaller ones, there's refuge in the shallows... 较小的鱼 可以在浅海寻求庇护
that has remained almost the same for hundreds of millions of years. 已经保持了数亿年 几乎不变
And yet, living in the same prehistoric swamps, 然而在同一片史前沼泽之中
the ultimate flying insects first appeared back in the ancient swamps. 最终能够飞行的昆虫 最早出现在古代沼泽中
They are the most abundant group of animals on Earth. 它们是地球上数量最多的动物