The primers in PCR are A. fragments of mRNA
B. designed to base pair with mRNA
C. free nucleotides
D. radioactive
E. needed to initiate the reaction

the animal that would be cutest if scaled down to the size of a cat? elephant

all these collisions do one thing, and that thing is explained in the last option. when dusst, rocks and ice collide, they harden and form giant layers of rocks or hard ice.

d)   to harden materials to form different parts of earth’s layers

hope it ,

bioteacher101