Level of Mercury falls in a barometer while taking it to a mountain. why? Needed ASAP

Explanation:

The higher the altitude of the instrument, the smaller the thickness (h) of the atmosphere above it. P = ρgh, so the higher the altitude, the lower the pressure as the altitude increases.

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.