Uhhhg, history {my lease fave subject! } who was the hellenistic (greek) mathematician who invented the compound pulley and is known for his work with the laws governing simple machines? a. pythagoras b. euclid c. archimedes d. hippocrates

crop rotation kepy different plants in the soil instead of once constintly. when switching out plants you have different nutrients being absorbed at different speeds and different roots growing differently therfore the spoil and water flow have to adapt and carry fresh nutrients to carry the constant changes that were going on in the soil.