(in order): acidic, basic, neutral
The pH scale determines how acidic or basic a solution is. It runs from 0 - 14, where 7 is neutral (neither basic or acidic).
A solution with a pH below 7 is acidic, and a solution with a pH above 7 is basic.
This means that the solution with a pH of 3.0 is acidic, the solution with a pH of 9.0 is basic, and the solution with a pH of 7.0 is neutral.