FACTUAL RIDDLES LV

1. After the White House, what is the second most-visited home in the United States?
2. What do the heads of the Departments of State, Labor, and Defense have in common?
3. A common convenience we all use really does what its name says it does only half the time. Nevertheless, we still call it the same thing when it does the other half. What is this common convenience?

Answers:

1. Graceland - the home of Elvis Presley, in Memphis, Tennessee
2. They are all Secretaries.
3. An elevator (It "elevates" only when it is going up.)