uestion 3: The amount of alcohol in a person's body is measured by__________

-the ratio of the weight of the alcohol to the body weight.
-the weight of the alcohol in a certain volume of blood.
-a special device the officer will stick you in the mouth.

The amount of alcohol in a person's body is measured by the weight of the alcohol in a certain volume of blood, typically expressed as a percentage. This measurement is commonly known as blood alcohol concentration (BAC).