What are 3 important influences in geography?

One important influence is climate ie many Canadians, especially from the cold Prairies like to move to Vancouver, BC because the climate is so much milder in the winter due to the proximity of the Pacific Ocean. Another important influence is topography, so that if a country is mostly mountainous, the cost of road building will be more expensive than on, say the prairies or on the coastal desert of Peru and northern Chile. Another important influence of geography is the presence of fertile soil such as in El Salvador from the ash of the volcanoes to grow coffee in, or the fertile floodplain of the Nile River in Egypt.

Ithink that the missing word is mixed