3x20 - Phineas and Ferb

When Ferb's cousins visit from England and challenge him to a soccer match, he and Phineas warp the walls of physics and build a high tech 3D stadium. Meanwhile, convinced that her relationship with Jeremy depends on her being more proper, Candace enlists the help of Ferb's British cousin, Eliza, to teach her the rules of etiquette. Back at Doofenshmirtz Evil Inc., Dr. Doofenshmirtz is sick in couch but forces himself to set off his \"If-A-Tree-Fell-in-the-Forest-Inator\", which causes any tree that falls to say his name.