Answer:
1. A huge paradox, or contradiction, is exposed towards the end of the scene: both Romeo and Juliet realize they have fallen in love with a member of an enemy house. They've fallen in love with something they're supposed to despise.
2. Romeo referring to love: "a choking gall and a preserving sweet"
3. Juliet: "my only love sprung from my only hate"
4. Juliet: "Was ever a book containing such vile manner so fairly bound?"
