Answer:
2, 3, 4, 5
Explanation:
I think this is right sorry if I get it wrong
It's an important part of the bird's ability to maintain its body temperature.
Air is a poor conductor of heat, so the air trapped among the feathers
prevents the loss of heat in cold atmosphere, and prevents overheating
in hot atmosphere. Much like our wearing several layers of clothing.
Answer:
C
Explanation:
A is wrong as 3 pathways are: classical, lectin, alternative
B is wrong - many C1-C9 act in other 2 ways EX C5
D is wrong - MAC consists of C5-C9
A population....... I think