Coal, a nonrenewable resource, is the most abundant fossil fuel produced in the united states. although environmental laws and modern technologies have reduced the impact on the environment from the production of coal, coal mining continues to disrupt nearby aquatic ecosystems. high concentrations of toxins and heavy metals can be carried as run-off into nearby ponds and streams. how would this affect the sustainability of the aquatic habitat?

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.

"a.) well–developed vascular system."