Please who knows ? Which is not a conjugate acid-base pair?

A. HNO3and NO3-
B. CH3COOH and CH3COO
C. H3O+ and OH-
D. HSO4-and SO4/2-

Diffraction is when light is bent around obstructions. which of the these observation about clouds would indicate diffraction? a) after rain storms, you can sometimes see rainbows. b) clouds are white or gray and cannot be seen through. c) on a cloudy day, the temperature tends to be cooler than a sunny day. d) the edges of dark clouds appear lighter. this