hi here is your answer hope it helps or then sry
Explanation:
the importance of oxygen for animals, researchers suspected that a sudden increase in the gas to near-modern levels in the ocean could have spurred the Cambrian explosion.
In making an experiment their are two types of variable that should be consider, one is the dependent variable and the other one is the independent variables. I the question that dependent variable would be the result or the effect of the gender of mice and the independent is the ways in determining it. So the variables should be fair if you want your result to have no bias. Thus the answer would be letter B. because it has the same variables but different in gender
Subduction i think,when they are pushed together one subducts forming a trench.im probably not right,sorry
Transfer of energy to another
