A bill working its way through the Legislature would make Minnesota the first state to mandate the sale of biodiesel, an alternative fuel made from vegetable oil or animal fat. The bill, which gets a hearing in the House Transportation Finance committee this morning (THURSDAY), pits farmers against the trucking industry. Opponents say there are too many unanswered questions about biodiesel, while supporters say the proposal is something the state can do to help farmers. Minnesota Public Radio's Laura McCallum reports...