Answer: a crack forms in the oceanic crust
Explanation:
A or b or c not d you chose
Yes , they are also very clean
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.
The form of energy would be C)Geothermal energy. Geothermal energy is heat within the earth so people can use this heat as steam or hot water to heat buildings and generate electricity
