The answer to your question is
x-rays
They may have ran out of oxygen, or they may not have been water dwelling snails, as not all are, lack of food, no flow of water into and out of the tank would cause them to run out of oxygen.
Answer:
See explanation.
Explanation:
With my current knowledge, this looks like erosion due to a combination of run off, acid rain, and sediment being carried in wind. It has happened over the course of millions of years, and will continue to happen for millions of years to come.
The atmosphere makes this acid rain precipitate and run off as well as makes the winds that erode at the rock.
The controlled variable is what stays the same . So it’s C . They are given different amounts but the same food.