Fluid, rolling, air resistance, and not sure about the last one.
So if it's 20% adenine (A) then it's 20% (T)...because A always pairs with T. That adds up to 40%....60% therefore is G+C...so you'd have 30% Cytosine (C) and 30% Guanine (G).
Answer;
DNA replication is semi-conservative.
The meselson-stahl experiment supported the hypothesis that DNA replication is semi-conservative.
Explanation;
The Meselson-Stahl experiment was an experiment by Meselson and Stahl that proved that the semi-conservative model by Watson and Crick was correct.
DNA replication is semi-conservative in the sense that the new helices formed after replication contain, one new DNA strand and one old strand from the parent DNA molecule.
