Answer:


Explanation:

Required
The units of A and B
From the question, we understand that:

This implies that each of
and
will have the same unit as 
So, we have:


The unit of t is (s); So, the expression becomes

Divide both sides by 


It is important to maintain septic systems in order to <span>prevent untreated sewage from contaminating groundwater</span>
Your answer will be Radio Waves .
That seems to be the only to make sense. Hope that helps u
Edit: You do mean Ridge?
Rocks near Mid-Ocean Ridge are younger than rocks near the trenches.
Seismic data shows oceanic crust is sinking into the mantle at the trenches.
Matching bands of magnetic rock are found on either side of the Ridge. Earth's magnetic fields change these bands over time.