Shifting cultivation is best described as a. growing cash crops instead of crops for one’s own use b. abandoning land as soon as the soil begins to degrade c. changing crops from year to year based on demand d. choosing which crops to grow based on climate zone

C. changing crops from year to year based on demand

Explanation:

Crop rotation is a good agronomic practice consisting of planned alternation of species in a given area. Experts consider it an effective way to reduce the environmental impacts of monoculture by improving long-term physicochemical and biological soil conditions. In addition, it reduces the incidence - and gives more efficient management - of diseases, weeds and pests (favoring the breakdown of their life cycle).

hello!

let's go through all of these words' definitions.

u-shaped valley - where the valley curves down like a u shape

corrie - similar to the hole created at the top of a volcano when it erupts, it's almost like a dent in a mountain

pyramidal peak - a mountain where the peak is very sharp, such as the matterhorn.

arete - two valleys separated by a thin mountain range

i'm going to assume you know how to read a topographic map, but in case you don't, feel free to comment.

now, let's figure out which one's which:

a - seems to be a mountain range separating two valleys, with a mountain running from top center to bottom center and two valleys on either side. therefore, i'd consider this an arete.

b - it looks like a dent into the mountain, like what a corrie is.

c - looks to be a valley, with two steeper sides curving up around the bottom of the valley which has a river in it. i would consider this an u-shaped valley.

hope this !