英语流利说Level3Unit3part1

Vocabulary Forms of Life

Mammals are covered by hair or fur,have a backbone and are warmer-blooded.

All female mammals produce milk for their young.

Reptiles are covered by scales and include snacks,lizards and turtles.

Reptiles have a backbone and are cold blooded,which means they often rely on external sources of heat.

Birds are covered by feathers and are warm-blooded.

Most birds can fly and many types of birds migrate great distances.

Most insect such as ants and bees have a small ,3 part body with 3pairs of legs.

Some insects ,like mosquitoes,spread diseases that cause the deaths of many humans.

Unlike animals,plants get the energy that they need from the sun.

Plants convert light energy,along with carbon dioxide and water,into chemical energy.