Blood Alcohol Content is the legal name for BAC but Blood Alcohol Concentration is sometimes used for simpler description. Blood alcohol content is usually expressed as a percentage of ethanol in the blood in units of mass of alcohol per volume of blood or mass of alcohol per mass of blood, depending on the country.
One way that society controls science is that the government can make certain experiments illegal. Hmm, maybe, but the apex answer is: People pass laws to restrict some research.
What are ways the government of Oceania controls its citizens? Rewrite history, fear of bad thoughts, fear of common enemy, monitor the citizens using cameras, corrupt babies and children (teach them to love Big Brother and hate most other things), rallies to generate support, and creation of a new laguage.