Butterfly is a kind of insects.It is as beautiful as flowers.It can fly.(本来这些句子用they are好一点,但是你规定要it can...)
Giraffe is a kind of mammals.it is as tall as a building.it can eat the leaves at the top of the trees.
Crocodile is a kind of reptiles.its teeth are as sharp as knives.it can kill other animals quickly.
Whale is a kind of mammals.it is as big as a large house.it can breath with lungs.
Elephant is a kind of mammals.it is as heavy as a car.it can carry heavy things.
Shark is a king of fishes.it swims as fast as a bullet.it can swim 60000meters per second.