The crab nebula is the remnant of an exploded star. the explosion was witnessed by chinese astronomers in the year 1054 ce. the crab nebula is 6500 ly away. this means the explosion occurred in what year? a.6500 bce b. 5446 bce c. 1054 bce d. 1054 ce ( explain reasoning)

B

Explanation:

A light-year is used for distance that the light has traveled for 1 year, so they saw the explosion in 1054 which means that it exploded back in the 5446, since it's 6500 light years away.

idk

explanation:

a mid-ocean ridge or mid-oceanic ridge is an underwater mountain range, formed by plate tectonics. this uplifting of the ocean floor occurs when convection currents rise in the mantle beneath the oceanic crust and create magma where two tectonic plates meet at a divergent boundary.a geomagnetic reversal is a change in a planet's magnetic field such that the positions of magnetic north and magnetic south are interchanged.