People with O+ blood cannot donate their blood to negative blood types, while people with O- blood can donate to any blood type. This makes them the "universal donor." However, they can only receive O- blood.
The best answer is D, birds.
For more information and details on the way a bird's respiratory system works:
https://asknature.org/strategy/air-flow-patterns-facilitate-efficient-gas-exchange/
Answer:
B) geology; theory of continental drift
Explanation:
Human forelimbs is used for a variety of functions, such as for eating.
Similarities: They are all made from the same basic anatomical structure classified as homologous structures.
They all have this structure inherited from a common ancestor.
