A pyroclastic flow is a dense, fast-moving flow of solidified lava pieces, volcanic ash, and hot gases. It occurs as part of certain volcanic eruptions. A pyroclastic flow is extremely hot, burning anything in its path. It may move at speeds as high as 200 m/s. Pyroclastic flows form in various ways.
If the substances preform the same in a variety of test, the they are the same. This is because they should always be tested in multiple categorys to see if they are the same or at least alike.
Answer: Well really the digestive, respiratory and circulatory systems all work together to make cellular respiration possible so i guess you could choose a or b
