Fact 1: When a river floods , that river deposits soil in flood plains.

Fact 2: Soil erosion harms farm and grazing lands and increases flooding and desertification.

Given the two facts above, answer the question "When a river floods, that river harms what?" with the following options: 
- most organisms
 - Basic units of the plant body.
 - streams and volcanoes
 - mountains and lakes
 - farm and grazing lands
 - oceans and ponds
 - swamp vegetation
 - Plant growth is reduced


 

     farm and grazing lands    