Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

For to synthesize glycogen purpose does liver use the excess carbohydrate.
For what purpose does liver use the excess carbohydrate?

If a substance has a ph value greater than 7,that indicates that it is base.
If a substance has a ph value greater than 7, what does it indicate?

The concentration of the hydrogen ion in a solution can be calculated when the ph is known.

The concentration of the hydrogen ion in a solution can be calculated when what is known?