Answer:
A light-year is a unit of distance.
Explanation:
Light moves at a velocity of about 300,000 kilometers (km) each second. So in one year, it can travel about 10 trillion km. More precisely, one light-year is equal to 9,500,000,000,000 kilometers.
Answer would be True since Russia became Communist in 1917.
Answer:
100% sure it's A, a crack forms in oceanic crust
Explanation:
It happens in the following order-
1. a crack forms in oceanic crust
2. molten rock rises up through oceanic crust
3. molten rock solidifies at the center of the ridge
Answer: volcanic activity
Explanation: The vast majority of volcanic activity on the planet occurs along the mid-ocean ridge, and it is the place where the crust of the Earth is born. The material that erupts at spreading centers along the mid-ocean ridge is primarily basalt, the most common rock on Earth.
This breed is called metamorphic rocks - rocks formed in the Earth's crust as a result of metamorphism, ie the change of sedimentary and igneous rocks due to changes in physical and chemical conditions