Describe the black holes using the basic equations from einsteins theory.

Black hole is described by singularity of Schwarzchild's equation.

Explanation:

Einstein's field equations consists of 10 sets of equations describing general relativity: Space time curves in presence of mass and energy.

Condition of black-hole came from Schwarzchild's solution to Einstein's field equation:

Black hole is described by singularity of Schwarzchild's equation.

It defines the event horizon of the Schwarzchild's black-hole.

i think they are all correct

explanation:

they seem good

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.