PLEASE HELP!

I’ll give extra points

Why are some galaxies’ spectra blueshifted rather than redshifted? question 4 options:

What happens when a rubber rod is rubbed with a piece of fur?

Select all the correct answers. which changes will increase the rate of reaction during combustion? decreasing the area of contact between the reactants adding more oxygen to the reaction removing heat from the reaction changing the reactants from solid form to powdered form lowering the exposure of the reactants to air