Whats 20x20? thank you

Several bird species feed in a certain species of tree. each bird species feeds in a different part of the tree. which statement is true of these bird species? a. they have adapted to different niches due to competition b. they have a carnivorous relationship with the tree species. c. they have adapted to different niches due to predation d. they have a symbiotic relationship with the tree species.

Pulmonary arteries carry highly oxygenated blood. true or false?

The offspring of a black cat and a white cat is a gray cat, it has the genotype bw if a black cat mates with a gray cat the chance that the offspring is white will be what percent?