Answer:
they occur at convergent plate boundaries
Answer:
Zicrons
Explanation:
The oldest of the zircons in the study, which came from the Jack Hills of Western Australia, were around 4.3 billion years old—which means these nearly indestructible minerals formed when the Earth itself was in its infancy, only roughly 200 million years old.
Which question
You never put which one
Answer:
The celestial sphere is a fictional sphere to which all celestial objects can be projected.
Explanation:
At any time an observer can see only the half of celestial sphere because the other half lies under the horizon. The celestial sphere is the medium used for sphere astronomy. The celestial sphere does not have a defined magnitude. It can be infinite or at least really big.
B is correct because the others are wrong, c is wrong because the reason they have varying states of matter is because pressure and a is wrong because mantle
