Answer:the possession of feathers
Explanation:birds are warm blooded animals , that possess feathers.these feathers cover their bodies and used for flight and warmth.their forelimbs are modified into wings,which fold into a Z shape at rest.feathers grow from the skin follicles and are replaced by scales on their legs.they possess oil gland to dress the feathers.
Other features of birds include
1) beaks with no teeth
2) fully ossified bones with air cavities
3)females with left ovary and oviducts only
Answer:
B) How often a disease occurs in a particular area or group of people
Explanation:
Epidemiologists study diseases in many different situations. Their main goal is to prevent diseases by using this information to plan and evaluate strategies.
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~Silver
Primary succession would most likely occur after a lava flow.