LOL... a couple of these have me stumped
Anyway, a couple of answers
Q. How far can a dog run into a wood?
A. Halfway, then he'll be running out of a wood
Q. What was the highest Mountain in the world before Mount Everest was discovered?
A. Ummm... It was still Everest, even tho no one had discovered it, it was still there.
Q. If the Vice-President of the USA was killed, who would then become president?
A. Sadly, it would still be George W. Bush

... the President doesn't change if the Vice President is killed.
Q. What 5 letter word becomes shorter when you add two letters to it?
A. Short. add to letters (e and r) and you get Shorter...