<span>Hard Rock
mining works when a narrow horizontal vein orebody will be mined by room and
pillar or a longwall method whereas a vertical narrow vein orebody will be
mined by an open stoping or cut and fill method. However, there are further
consideration needed for the strength of the ore as well as the surrounding
rock. In addition an orebody hosted in strong self-supporting rock may be mined
by an open stoping method while an orebody hosted in poor rock may need to be
mined by a cut and fill method were the void is continuosly filled as the ore
is removed. </span>
The answer to your question is the letter A
Earth is basically from matter, all the matter around the Universe came together to form Earth, the only way for Earth to grow much bigger is if there was an unlimited supply of matter, there isn't and therefore Earth cannot get much bigger than it is now.
Cartography and meteorology
The type of energy is thermal.