3. which sentence best describes mass movement?
a. the movement of particles within an atom b. the downhill flow of soil and rock resulting from gravity c. the downhill movement of animals due to heavy snow in their normal home d. the steady pace of air bouncing off a mountain

The answer is B. The downhill flow of soil and rock resulting and rock

Mass movement is the movement of surface material caused by gravity ,
the downhill flow of soil is commonly known as landslide is a type of mass movement, so does the downhill flow of rock resulting from gravity ( commonly known as rockfall)

Humid continental climate is found in the interior of continents between the 30 and 60 degrees latitude, but usually above the 40 degree line.   40 degrees north of the equator means less direct sunlight and therefore less warmth.   this climate is mainly found in the northern hemisphere since there are no major landmasses in the southern hemisphere.  if you live in northern indiana, you know all about humid continental because that is the climate type you have!