Convergent boundaries are areas where plates move toward each other and collide.
Subduction zones occur where an oceanic plate meets a continental plate and is pushed underneath it. Subduction zones are marked by oceanic trenches. The descending end of the oceanic plate melts and creates pressure in the mantle, causing volcanoes to form.
Orogenic belts occur where two continental plates collide and push upwards to form large mountain ranges.
Transform boundaries occur when two plates grind past each other with only limited convergent or divergent activity.
... maintain a position of power.
Quackery has existed all throughout human history, and probably pre-dates the emergence of effective medicine.
Quackery is still abundant ...