1 drink = 1/2 pint of beer or 1 glass of wine or 1 single spirits. 1 unit of alcohol = 10cc of alcohol. So, a small glass (125cc) of 12% wine is 12.5 * 0.12 = 1.5 units.
How many units of alcohol do you drink on a typical day when you are drinking?
How often have you had 6 or more units if female, or 8 or more if male, on a single occasion in the last year?