Which tools do astronomers use to determine the effects of collisions between galaxies

Which types of seismic waves travel through earths interior? select all that apply. a) l waves b) p waves c) s waves

Scientists believe that differences in cause hot, plastic-like rock in the asthenosphere to rise toward earth's surface. a. density c. weight b. magnetism d. composition c. conduction. d. density.

What is the border between layers a through f and layer g called?