To predict earthquakes. geologists look for a combination of the following signs:
foreshocks, increases in well water levels, and decreases in radon gas in ground water
foreshocks, increases in well water levels, and increases in radon gas in ground water
foreshocks, decreases in well water levels, and increases in radon gas in ground water
aftershocks, decreases in well water levels and decreases in radon gas in ground water

the correct answer is blue and green.

a visible spectrum is electromagnetic spectrum color that can be seen by a normal human being by a single wavelength of light. the visible light spectrum is the range of wavelengths that make up visible light. the visible light spectrum passes through a prism enabling the rainbow reveals all the colors in the spectrum. these range from red, orange, yellow, green, blue and violet.

answer; is roughly two weeks;