Answer:
the flat horizontal lines indicate phase change
Explanation:
As the substance changes phase from solid to liquid and liquid to gas, the temperature remains contant due to latent heat energy.
Energy is being used to break the intermolecular bonds during phase change, therefore there is no change in temperature.
There are three parts to this theory. The first part states that all organisms are made of cells. The second part states that cells are the basic units of life. These parts were based on a conclusion made by Schwann and Matthias Schleiden in 1838, after comparing their observations of plant and animal cells.