Answer:
Black holes are astronomical objects that have such strong gravity, not even light can escape. Neutron stars are dead stars that are incredibly dense. ... Both objects are cosmological monsters, but black holes are considerably more massive than neutron stars.
Explanation:
Hydropower is one of the oldest renewable resources and has been used for thousands of years.
Answer:
magnesium
Explanation:
magnesium is in Group 2, in the periodic table. this means that it has 2 valence electrons. the less valence electrons an element or atom has, the more reactive. Selenium has 6 valence electrons. as a result, Mg is more reactive
I think it will be B. Hope it helps :)