What was the total demand by all counties for water from the sweetbriar river basin in 1970? what is it projected to be in 2020?

the last option, alcohol and salt.

Explanation:

1) A solution has one or more substances dissolved in it. Then a solution may have more than one solute.

2) Solute is the substace that is dissolved and solvent is the substance in which the solute is dissolved.

3) Water is the solvent the most widely used solvent.

4) At the beginning there is not doubt: salt is the solute dissolved into the solvent water to form the aqueous solution of 2% salt.

5) Adding alcohol is adding a new solute that will also mixed and get dissolved into the water, that is why alcohol is also a solute in the new solution with three components: two solutes and one solvent.