Answer:
E. Variations in Earth's orbit occur gradually over 100,000 years.
A true-breeding<span> organism, sometimes also called a purebred, is an organism that always passes down certain phenotypic traits (i.e. physically expressed traits) to its offspring.</span>
12/44 = 0.2727
(X100)
= 27
( therefore the percent mass of carbon in carbon dioxide is 27%)
Enzymes speed up the chemicaal reaction .