Plz i really need it i am in a test and i am having a lot of trouble with the whole thing i have went through all of the questions and understand none of them

The first answer is Susan B. Anthony.

The second answer must be the spinning wheel. The spinning wheel has been around long before the dawn of the 20th century.

what do you                                                                                                                                              

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.