Learn about six different construction vehicles in Whose Big Rig?, a guessing-game board book. This nonfiction follow-up to Whose Truck? features six kinds of specialized rigs used to construct a light-rail system--a tunnel borer, an excavator, a bulldozer, a tie dragon, a tamping machine, and a bucket truck--with five different parts of each rig properly labeled. The answer to each inquiring refrain of "Whose rig is this?"...