拖拉机世界上最早的拖拉机称为蒸汽拖拉机。动力是蒸汽机、铁轮,很笨重,外形很象修公路用的压路机。这种原始轮式拖拉机生产效率低,消耗大,每台一个作业班次要喝掉4吨水,烧去2立方米多的木材。后来,人们加大拖拉机的后轮,并在轮缘上加凸爪,防止下陷和打滑,机后拖挂农具,下田作业。 Tractor The earliest tractor in the world is called a steam tractor. Power is steam engine, iron wheel, very bulky, very much like the shape of the road with a road roller. This primitive wheeled tractor is inefficient and costly, consuming 4 tons of water per one shift and burning more than 2 cubic meters of wood. Later, people increased the rear wheel tractor, and the flange plus claws, to prevent sag and slippery, after the tractor farming machine, Shimoda homework.