What led scientists to discover cells and cell theory? The invention and improvement of microscopes.
Eyeglasses led to the discovery of cells.
The invention of the internet.
The invention of satellites.

The invention and improvement of microscopes.

Explanation:

The internet and stellites were not invented until after this, eyeglasses were invented but they could not see things that small

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

they had the law tat factories that produces smoke cannot be built near residential buildings.

building of proper sewage system was done to ensure that the waste is carried away from the humans so that they do not get diseases from it.

also they built water systems to provide water in those areas which are drought prone.