The remaining teams continue in the fifth leg of the race.

When Bart fails to turn in his homework, Mrs. Krabappel sends a letter home about Bart's behavior. Despite Bart's best efforts to intercept it, Homer reads the letter, and he and Marge visit Principal Skinner for a parent-teacher conference. Furious, Homer punishes him, but Marge takes a more sympathetic approach. When Bart realizes he can pit Homer and Marge against each other to his benefit, his scheming reaches new heights.

Sonny hosts a "Walk-A-Thon For Books" for kids and gives each of them Tawni's Extreme Skinny Jeans. When Chad hears of this, he then hosts a "Walk-A-Thon Against Books" and also sells the skinny jeans to compete with Sonny.

Fourteen new celebrity candidates begin a new "job interview" to win $250,000 for the charity of their choices.

Stewie pulls a "Tootsie" in order to star in the American version of Jolly Farm Review.

Meanwhile, Peter makes Lois feel bad about her age, and she gets a bit jealous of Meg’s new boyfriend.

Bill Carstanjen, COO of Churchill Downs, Inc., the corporation famously known for its Kentucky Derby, goes undercover at his own racetracks where he faces his fear of horses head-on, and is unable to hold back tears after working for one employee.

Directly following the attack on Pearl Harbor, Seargent John Basilone ships out to fight the enemy somewhere in the Pacific, and a young journalist called Robert Leckie enlists in the Marine Corps. Sidney Phillips ships off to boot camp after saying farewell to his friend Eugene Sledge, who cannot go with him due to a heart murmur. Eight months later, Phillips and Leckie, having completed boot camp are sent to secure a airfield on Guadalcanal, and to help defend it against counterattack.

Shelby's desperate dash for cash is halted when he crashes in the swamp. A monster gator stalks the S&S boys, pushing Jimmy to his breaking point. At Rygaard, Gabe competes against his own team and at Browning, Jay recruits DJ and Cody for a dangerous environmental mission. At Conner, a giant load breaks the belly hook off the chopper, grounding the heli-loggers.

When the Gunderson boys – Brandon, Gary and Robby – hire Ron Snuffkin to pretend to be their father after their real father goes to prison, they find out that there's more to their "fake" dad than meets the eye. Ron has to enroll them in school, convince Robby's teacher to keep him in her class, sweet-talk the principal, locate mint-condition toy soldiers at his grandmother's house and avoid a thug who wants his money.

Kitty's newfound fame creates havoc for Luc and Sarah, as Luc faces possible deportation. Meanwhile, Nora swallows her pride and reaches out to Tommy to help her save the company from the Walkers' longtime nemesis, Dennis York.

The team reopens the case of a dock worker who was moonlighting as an indy-circuit wrestler until he was shot dead in 1986, and Valens secretly looks into a lead on the man who mugged and raped his mother.

Gabrielle and Angie head out to New York to track down Ana and Danny, and a chance encounter with supermodels Paulina Porizkova and Heidi Klum, Gaby's former co-workers, leads the former top model to an unexpected revelation about herself. In the meantime, Mike tries to prove to Susan that he is a man with a capital "M" after he feels emasculated by her, and the Scavo family is surprised to see Preston back from Europe... accompanied by a hot Russian gold digger. Bree discovers a surprising connection to her new employee and Katherine feels confused regarding her feelings towards Robin.

Ben and Cam meet with a Japanese buyer but their jeans don't turn out the way they wanted them to. Rene has trouble locating a huge pile of cash and Rachel and Darren experiment with Ecstasy.

Gajeel starts fighting and ends up in a fight with Natsu. Makarov fights with Phantom Lord Wizard, Jose, and being cathed in one of the Element 4 Magic. He loses his magic power and Fairy Tail army leaves the Phantom Lord. Lucy is rescued from the Phantom Lord guild by Natsu.

Engineer Jem tries to smash a land speed record with the help of a single fire extinguisher, a go kart and a well oiled spanner. In an experiment that you really shouldn't try at home, Jem builds himself a go-kart attached to a staggeringly powerful fire extinguisher that uses the laws of physics to fire him along a race track and into the record books.

With oil prices rising every year, Dallas takes on an issue that concerns all of us. What will we do when the oil runs out? At the moment, across the globe, we use 85 million barrels of crude oil every single day but the fact is that our oil supplies can't last forever. With Richard Branson as one of his guides, Dallas looks at the future of oil explorations, and tells us what this means for our wallets.

Liz goes behind the scenes of the real CSI (the Forensic Science Service) to meet the scientists working with the police to solve real crimes. With one crime, three suspects and no DNA evidence, Liz launches her very own forensic investigation to catch the bad guy.

Bang Goes the Theory is co-produced with The Open University. For more ways to put science to the test, go to www.bbc.co.uk/bang and follow the links to The Open University.

Quiz show presented by Victoria Coren in which knowledge will only take you so far, as patience and lateral thinking are also vital.