Level3 Unit3 Part1 Vocabulary -Forms of life
mammals（哺乳类动物） are covered by hair or fur（毛皮）,have a backbone（脊椎） and are warm-blooded（温血的）.
All female（雌性） mammals（哺乳动物） produce milk for their young.
Reptiles（爬行动物） are covered by scales（鳞片） and include snakes,lizards（蜥蜴） and turtles（乌龟）.
Reptiles have a backbone and are cold-blooded,which means they often rely on（依靠） external（外部的） sources of heat（热度）.
Birds are covered by feathers and are warm-blooded.
Most birds can fly and many types of birds migrate[ˈmaɪgreɪt] 迁徙 great distances.
Most insects such as ants and bees have a small,3-part body with 3 pairs of legs.
Some insects, like mosquitoes , spread（传播） 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（二氧化碳） and water,into chemical energy.
Mosquitoes cause the deaths of more humans than any other animal.
Insects such as ants and bees live in well-organized（组织有序） colonies（聚居地）.
Most mammals live on land,but some live in the sea.
