Why would your answer you gave to part a motivate hollywood to use more realism in special effects?

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.

no every country is held to the same degree as others just some member countries such as the usa and germany are more economically sound so the need to show there support to all others  

the anwser is a) to prevent military conflict