B, d. is earth's orbit around the sun
Answer: dolomite rock that becomes soluble over time
Explanation: ageing infrastructure that combined with volatile climate that are major causes of the appearance of the sinkholes
Answer:
Afghanistan's mountains have kept the country from ever being invaded.
Explanation:
Afghanistan is a country in terrible conditions, and this is not the case just nowadays but it has been like that for a very long time. Despite all of the internal troubles of the country and it seems to be very weak in pretty much every sector, it has never been invaded in the past few centuries, and very rarely in the more distant history and always it has been short-lasting.
The main reason for this has been the mountains and the general geography of the country. Very high and rugged mountains are separating the country from potential invaders. Even if an invading force manages to go through the mountains, it will suffer great losses just by doing so, and what comes next is desert and more rugged terrain, which will further damage them, so by the time they engage in battle, they will be too weak to conquer Afghanistan.
Gypsum is a chemical sedimentary rock.
Because the orbital period and rotational period are the exact same.
