The main reason for the wall's construction had always been defense. Since China's first dynasty, the empire faced a near-constant threat of attack from the nomadic tribes to the north. This included those famed Mongols as well as lesser-known groups like the Xiongnu and the Göktürks.
Answer:
Natural elements such as metals, wood, and recourses such as H20,C02,and o2.
Iron, copper, and aluminum are 3 metals that are commonly used in todays economy.
A stationary front is depicted in the picture at L. A stationary from is a narrow zone separating two air masses in which neither air mass is displacing the other. When this occurs there is a stall in the motion of the front. The blue triangles point away from the cold air and the red semicircles point away from the warm air.
Answer:
Actually the radiation belts are a negative side effect of the earths magnetic field as well as the Suns magnetic field. As cosmic particles collide with particles in the atmosphere they decay into energetic protons while the outer belt is mostly electrons made in geomagnetic storms.
if it didn't exist we could launch more satellites or have larger space stations without the worry of perpetual radiation exposure as for earth there would be no negative consequences to the loss of the energy.
