Contour lines determine the steepness of the land by how close they are together. Generally, contour lines rise to a particular scale (e.g. a line for every ten metres), therefore, if the contour lines are closer together then the height of that particular area has risen more steeply than if the contour lines are further apart where the steepness has increased more gradually.
C. railroad...............
The correct answer is A. Increased use of pesticide.
The name 'green revolution' is very misleading, because it makes you believe that is something positive about the nature. In fact, it is something that made a lot of harm to the environment with pollution and increased erosion caused by the usage of chemical fertilizers and pesticides and herbicides, caused problems in the societies because a lot of crops needed for people to feed themselves where destroyed so that other plants can be produced.
<em>Jet Streams.</em>
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<em>Hope it can help !!!</em>