Both primary and secondary succession begin with pioneer species that- a use up all the existing resources and prevent establishments of non-native organisms
b modify the area and allow larger and more complex organisms to appear
c change the area and make it safer from predatory organisms
d invade the area so that new organisms cannot be established

the answer is; comparing the frequency of collisions with and without the device

this makes the anti-collision system an independent variable and the collisions a dependent variable. if there are fewer collisions with an anti-collision system that without, then it can be stated that the system is a success. essentially, collisions under an anti-collision system are compared with the frequency of collisions by cars with the human drivers.

it's     c       this is a cell (b) with a nucleus (c) containing dna (a). the dna is organized into chromosomes (d). a section of the chromosome that codes for a trait is called a gene (e).

the darker peppered moth species were favored due to the fact that the industrial revolution had made all the nearby trees a darker color instead of white.

the answer is cell division : )