用英语介绍一种生活在水中的动物（6—8句即可）

crocodile(鳄鱼） is a kind of animal living in the river. because of its ferocity, people are all afraid of it, or escape from it when see it.

Like all animals living in water, frogs spend their lives near water because they must return to the water to lay their eggs. Frog eggs are laid in the water. When they hatch into tadpoles, they breathe with gills and swim using a tail. As they mature, they lose their tail, and they develop lungs for breathing air. In harsh climates, frogs bury themselves in sand and mud and hibernate (sleep very deeply) through the cold winter. Frogs eat insects, catching them with their long, sticky tongue. They also eat small fish and worms.