Answer:
When a substrate is added in water, the enzyme will cause the substrate to dissolve in water. Increase in temperature will cause better functioning of the enzyme and more solute to be dissolved until an optimum temperature. Optimum temperature can be described as the temperature at which the activity of the enzyme is highest.
After optimum temperature is reached, the enzyme will get denatured and the substrate will no longer be able to dissolve in water.
A to move around is the answer
A heterogeneous mixture composes of non- uniform components, so the concrete would be the answer, because you can tell the components from one another.
Soil and rocks maybe. not too sure.