Pls help plsbnhvbnkjhgbvbnmkjhgv m

How can you keep track of variables in a science experiment?

The frequency of alleles in a population that is in hardy weinberg equilibrium? a . changes in each successive generation b. is less important than the frequency genotypes c. shows evidence of the process of natural selection d. remains the same over several generations

How can we use spectral lines of light coming from the superclusters to identify which is receding from earth at the slowest rate.