An idea that the universe originated with an explosion is supported by repeated observations of light from distant galaxies traveling away from Earth. An idea that has been tested repeatedly and is supported by repeated results is MOST likely a

increase soil erosion                                             reduce soil erosion

cattle grazing                                                         hydroseeding

deforestation                                                         contour plowing

                                                                                planting vegetation

plant roots basically hold the top soil

together and stop soil erosion because

in such situation top soil is not removed

during flood but cattle grazing causes

soil erosion because cattle consume the

grasses and herbs and top soil is exposed.

same situation occurs because of

deforestation, the trees and plants are cut

down to expose top soil which causes soil

erosion

a- all cells come from pre-existing cells

helicase, i think thats it