A bus completes a trip from City A to City B with an overall average speed of 19 m/s. However, the bus made a rest stop for 15 minutes during the trip which brought the average speed down. Only considering the time that the bus was moving, the average speed of the trip was 22.5 m/s. How far apart are City A and City B?

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.

i don't understand. explain it clearly