Rewrite the second to fifth paragraphs of the text "Bailuyuan" into explanatory paragraphs.

Rewrite the second to fifth paragraphs of the text "Bailuyuan" into explanatory paragraphs:

Egret is a kind of birds, with a thin body, about 60 cm long, iron beak, thin neck, blue feet, long legs, white feathers as snow and streamlined structure.

Egrets are well-proportioned and have suitable pigments. Guo Moruo once commented on its shape: "Snow-white withered hair, streamlined structure of the whole body, long iron beak, blue feet, one point longer, one point shorter, one yuan too white and one yuan too black."

The exquisiteness of egrets dwarfs other egrets. In contrast, the white crane is too big and stiff, and the pink ibis and grey herons are more delicate. But compared with egrets, it is not only a little bigger, but also unusual, and can't be compared with egrets.