Misc: How many Jackson brothers are there?

Questions

"You cannot escape the -------------- of tomorrow by evading it today."- Abraham Lincoln?

"He'll regret it to his ----------, if he ever lives that long."- Frank Nugent?

"Here is the test to find whether your ------------ is finished: if you're alive, it isn't."- Richard Bach?

"You cannot simultaneously prevent and prepare for --------."- Albert Einstein (1879-1955)?

"You can't depend on your eyes when your ---------- is out of focus."- Mark Twain (1835-1910)?