What law of motion corresponds with the following statement? "a bird pushes down on the air with its wings in order to fly"-first law-second law-third law?

Third law, which states that for every action, there is an equal and opposite reaction... btw this is a physics question and not a biology question. 

Allow large amino acids through

Ben should classify a mango tree as an autotroph because it makes its own food with photosynthesis. he should classify algae as a heterotroph because it relies on other living things to get food.