How many familiar acronyms or initialisms can you think of that start with S and have only three letters? Twelve are listed below in alphabetical order.

1. SAE - Society of Automotive Engineers 

               (Certifies viscosity of motor oil)

2. SAG - Screen Actors' Guild

3. SAS - Scandinavian Airlines System

4. SAT - Scholastic Aptitude Test

5. SEC - Securities and Exchange Commission

6. SLR - Single Lens Reflex (camera)

7. SNL - Saturday Night Live (TV show)

8. SOL - _____ Out of Luck

9. SRO - Standing Room Only

10. SSN - Social Security Number

11. STD - Sexually Transmitted Disease

12. SUV - Sport Utility Vehicle