Help please.?

What kind of action is a cause of air pollution

You are working in the lab and are working with the same element but with varying isotopes of the element. you are working with c-11, c-13, c-14, and c-15. what is the average atomic mass of this element? (use periodic table) a- 12 b-15 c-14 d-13

The first generation of offspring from the cross of two parents is called the a.f1 generation b.f2 generation c.short generation d.p generation