The delivery route for a mail truck is pictured below. Each square represents a city block, and the path of the truck is represented by arrows. The truck began and ended at the same location What was the displacement of the mail truck

c)as speed changes, wavelength and frequency change.

everything changes!

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.