What does it mean to be happy​

Which theory of color vision most accurately describes the process of color vision at the level of the retina?

What was love canal? what was the significant hazardous waste event that happened and when did it occur?

What happens when two galaxies approach each other? a. they form a black hole. b. they merge because of the strong gravitational pull they exert on each other. c. they shred each other into smaller galaxies. d. they form a supernova. e. they repel each other away because of their strong gravitational pull.