Earthquakes on plate boundaries happen more because the plates all move in different directions in a tectonic environment so they collide against each other which makes them more frequent. Earthquakes rarely happen in intra-plate environments but along faults in normally stable interior of the plates. If this doesn't make sense, ask me to reword it for you !
Answer:
Organelle (oppitional, I don't put this on my paper but you can if you want), cells, tissues,
Explanation:
The most basic reason that cells are stained is to enhance visualization of the cell or certain cellular components under a microscope. Cells may also be stained to highlight metabolic processes or to differentiate between live and dead cells in a sample.