The substance must be able to alter its physical characteristic (for example, its color) in accordance to a change in pH. One example of this is litmus paper, which becomes red under acidic conditions and blue under basic conditions.
Answer:
The answer is a. they are much like empty rooms.
Explanation:
Cells are pretty much the opposite of empty rooms. There are many organelles and processes happening in them, so there's no space for empty rooms. Even when there are spaces, which anyway would be full of liquid, these spaces have a purpose.
Answer:
Erosive Forces:
•light particles float
• some particles dissolve into water
• abrasive forces wear down rocks
