Question

but what caused the earth to tilt? long, long ago, when earth was young, it is thought that something big hit earth and knocked it off - kilter. so instead of rotating with its axis straight up and down, it leans over a bit. what does the word tilt mean as used in these sentences? a skip b spin c move d lean

Explanation:

To determine the meaning of "tilt", we analyze the context. The text says Earth's axis doesn't rotate straight up - down but "leans over a bit". Option A "skip" and B "spin" (which refers to rotation, not leaning) don't match. Option C "move" is too general. Option D "lean" matches the description of Earth's axis position.

Answer:

D. lean