When a scientific experiment is carried out in a controlled setting, all variables are kept the same except for the C. experimental. Experimental variables are the things you are studying in the experiment and it is the only variable you can change.
Answer
Answer:
Rivers often start from the mountain streams and contain high amounts of oxygen. Rivers and streams grow larger as these waters merge. Rivers pick up sediments from the land as they flow. Lakes support many varieties of organisms, including plants in shallow,
A, C, then B. <span>Hope this helps! Brainliest would be appreciated!</span>
