D. Twenty countries whose people share a common religion and cultural heritage
A commucist organization formed in Cambodia in 1970 became a terrorist organization in 1975 when it capture Phnom Penh and create a government that killed an estimate three million people
Democratic Kampuchea
Answer: Mantle plumes, Continental rifts, island arcs, and Continental arcs
Explanation:
Mantle plume is the mechanism of convecting abnormally hot rocks within the Earth's mantle. The plume head partly melts on reaching shallow depths, the plume is often invoked as the cause of volcanic hotspots.
Continental rift refers to the belt of the continental lithosphere where the extensional deformation (rifting) is taking place. Continental rift zones have important consequences and geological features, and if the rifting is successful, leads to the formation of new ocean basins.
Island arcs are long chains of active volcanoes with intense seismic activity found along convergent tectonic plate boundaries. Most island arcs originate on oceanic crust and have resulted from the descent of the lithosphere into the mantle along the subduction zone. They are the principal way by which continental growth is achieved.
Continental arc is a type of volcanic arc occurring as an "arc-shape" topographic high region along a continental margin. The continental arc is formed where two tectonic plates meet, and where one plate has continental crust and the other plate has an oceanic crust along the line of plate convergence, and a subduction zone develops.
