Which practice produces farmland with poor soil ?
a. slash and burn
b. crop rotation
c. thinning
d. shelterwood harvest

A. Slash and burn

Explanation:

The slash and burn method is a very harmful method for the soil, as well as for the whole environment. This method is consisted in total removal and burning of the vegetation in certain area in order to free up space for farmlands. The slash and burn method is mostly used in forested areas, the majority of which are tropical rainforests. The soil in this areas is relatively good, but its top part is very loose, so once the natural protection of the vegetation is removed, it is heavily affected by erosion. This leads to a situation where the soil can only be used fro few years before it becomes almost unusable, so the people continue to slash and burn other areas, living behind barren land with very poor soil.

sonar maybe? ? i dont know the choices

the industrial development of cities in the ruhr area in the nineteenth century is described. the research was based on english and german language sources. several factors that shaped growth and paths of the cities were categorized and analyzed. they are locations, resources, traditions, entrepreneurs, and technological developments. locations and resources were the most important among them; other factors may be regarded as consequences from locations and resources. among the cities, bochum, essen, gelsenkirchen, and dortmund had the richest resources and most favorable locations in the transportation network and grew to be the largest cities in the ruhr area near the end of the nineteenth century. riverside location was also a favorable factor for the development, as shown in the development of duisburg on the confluence of rhine and ruhr. resource distribution can explain the rise of textile industry, metallurgical industry, and coal and iron industries, and the northward progression of the mining industry. tradition was an important factor for cities such as krefeld, barmen, elberfeld, solingen, and remscheid, which experienced development based on their traditions through the nineteenth century. various entrepreneurs exerted influences within and beyond the local level over the ruhr area. technological development stimulated the northward progression of the mining industry and the deep connection between the coal and the iron industries.