The following is the introduction of frogs:

Frogs are amphibians, belonging to Chordata, Amphibia, Anura and Ranidae. Its adult has no tail. Its eggs are laid in water, fertilized in vitro, hatched into tadpoles, and breathed through gills. After the mutation, adults mainly breathe through the lungs and skin. The upper jaw has teeth, usually plow teeth. Shoulder straps fix the chest, the vertebral body is uneven, and the transverse process of sacrum is columnar; There is no mesenchymal cartilage between the two joints at the toe. The eardrum is obviously hidden under the skin, and the skin is smooth or warty. Tongue is generally oval, and there are many notches at the back end.

Frog body can be divided into three parts: head, trunk and limbs. Frog has four toes on its front foot, five toes on its back foot and webbed feet. There are two slightly bulging bags on both sides of frog's head. That's its eardrum. Frogs can hear sounds through it.

Frog's back is green, smooth and soft, with patterns, and its abdomen is white. You can hide it in the grass, which makes it easier to catch pests and protect yourself. Its skin can also help it breathe. Its airbag is only available to male frogs. Frogs hunt with their tongues, which contain mucus.

Refer to Baidu Encyclopedia-Frog for the above information.