Next to mammals,birds are the most useful to man.Birds are an animal with feathers;they have two legs,two wings and a beak;they are warm_blooded.They lay eggs and the young hatch from the eggs.Although there are thousands different kinds of bird,according to the movement,they are classified into three main groups:birds that fly,birds that swim and birds that run.
The first group,birds that fly,has structure which suitable for flying.This group has two forelegs which are very developed,strong body and light bones;these features help them fly quickly.Pigeon,sparrow and parrot are some examples.In addition,each bird has its own way to fly.Some birds slap their wings before they fly like:pigeon,robin,parakeet...while some others rise up their wings follow the air such as eagle,hawk,falon.Normally,this group has strong,short beak so they usually eat seeds like:chestnuts,specks.This type of bird are always being kept as pet because of their special features,people keep them for entertaining.
The second group,birds that swim,has structure which adapt to swim.They have two less strong wings,short legs;especially,they have a thin membrane that help them swim easier than fly.Penguin,duck,goose are some typical birds for this group.When they move on face of water,they use their legs to push against the stream and move away.These birds have pointed and curved beaks so they are able to catch and eat fish,sprim, screws.With these features,people keep them for food:meat,eggs.
The last group,birds that run such as pheasant,ostrich; has parts comform with run.This type of bird has two developed legs,two weak forelegs;therefore,they can run very fast.For example,in desert,an ostrich can run more faster than a horse,an ostrich can run 200 meter per minute while a horse just run 150 meter per minuter.This group belongs to type that eats meat of died animal because they have large,strong beak so they can tear meat into many pieces.This birds always live in desert,hard weather,thus they have special habit _ running.
We can see that each kind of bird has its own features,so they suitable for different environments and habits;and they belongs to different kind of groups.
The first group,birds that fly,has structure which suitable for flying.This group has two forelegs which are very developed,strong body and light bones;these features help them fly quickly.Pigeon,sparrow and parrot are some examples.In addition,each bird has its own way to fly.Some birds slap their wings before they fly like:pigeon,robin,parakeet...while some others rise up their wings follow the air such as eagle,hawk,falon.Normally,this group has strong,short beak so they usually eat seeds like:chestnuts,specks.This type of bird are always being kept as pet because of their special features,people keep them for entertaining.
The second group,birds that swim,has structure which adapt to swim.They have two less strong wings,short legs;especially,they have a thin membrane that help them swim easier than fly.Penguin,duck,goose are some typical birds for this group.When they move on face of water,they use their legs to push against the stream and move away.These birds have pointed and curved beaks so they are able to catch and eat fish,sprim, screws.With these features,people keep them for food:meat,eggs.
The last group,birds that run such as pheasant,ostrich; has parts comform with run.This type of bird has two developed legs,two weak forelegs;therefore,they can run very fast.For example,in desert,an ostrich can run more faster than a horse,an ostrich can run 200 meter per minute while a horse just run 150 meter per minuter.This group belongs to type that eats meat of died animal because they have large,strong beak so they can tear meat into many pieces.This birds always live in desert,hard weather,thus they have special habit _ running.
We can see that each kind of bird has its own features,so they suitable for different environments and habits;and they belongs to different kind of groups.
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