In the rock cycle, what forces can change sedimentary rock to igneous rock?

The earth's internal process which drives seafloor spreading is

What was apartheid and how did it restrict the rights of non-whites?

Which events occurred during the space race? check all that apply. (a) nasa was established. (b) yuri gagarin orbited earth. (c) the soviet union launched salyut. (d) the united states launched skylab. (e) the united states launched explorer 1.