Compressional stress on rock can cause strong and deep earthquakes, usually at normal faults reverse faults strike-slip faults anticlines

Which one of the following research methods can show cause and effect

What is the gravitational attraction between a dating couple whose centers of mass are 0.630 m apart if the boy weighs 715 n and the girl weighs 465 n?

What would be the radius of the earth if it had its actual mass but had the density of nuclei? express your answer to two significant figures and include the appropriate units.