Misc: What is the largest inhabited castle?

Questions

"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)?

"You can't have a long successful career without a ------------."- Nolan Ryan?

"You can't make a ----------- out of a Sow's Ear."- Jonathan Swift?

"You can't shake hands with a ----------------."- Indira Gandhi (1917 - 1984)?