19. most of the information about earth’s interior was obtained by studying (1 point) a. earthquake waves b. rocks of the ocean crust-my answer    c. meteorites d. rocks in deep wells 20. the continental crust has the average composition of (1 point a. gneiss b. granite c. basalt d. limestone-my answer    21. the greatest concentration of metals occurs in earth’s (1 point) a. oceanic crust b. continental crust c. core -my answer    d. mantleam i right?