One of the strangest races in history is about to begin. The judge raises the starting gun and says,"On your marks, get set...'' BANG! Who will win this 40-yard race? Will it be the ostrich with its long legs? Or will it be the highly trained football player? Could the squirrel rush past them all?    Don't worry. It's not a real race. Last week, Scientific American magazine asked professor Peter Weyand who would win an imaginary race between an ostrich, a football player, a pig, a squirrel, and an elephant. Weyand teaches physiology. He studies the way animals move.    According to his knowledge of how animals  _ , here's how the race might go:    The ostrich runs out of the starting gate neck and neck with the football player in second, the gray squirrel running third, and the pretty pink pig in fourth.    Forty yards later, at the finish line, the heavily feathered bird beats the speeding human! The competition isn't terribly close between the ostrich and the football player, but in a surprise move, the pig moves fast and manages to beat the squirrel by a nose. Pigs don't look like they're built for speed, so its third-place finish is a bit of a shock.    How does Weyand explain the Animal Kingdom's speedy match?    "The easiest way to explain why the ostrich is fast is that it has long legs,'' he says. Most of the ostrich's leg muscles are high up on its short thighbones. Its long, light legs allow the bird to go faster and keep speed easily. When running, an ostrich's highest speed is about 35 mph. Elephants and squirrels actually run at the same pace. But because squirrels can accelerate quickly, the huge elephant would lose. Pigs can't speed up as fast as squirrels, but they can run faster. Pigs that live in the wild can run close to 16 mph, and squirrels can run at about 14 mph. The author shows his research by describing a scene of   _  .
an animal game a physiology class an imaginary race a school sports meeting