Hundreds of millions of years ago, when fossil fuels were formed, large amounts of a carbon dioxide were trapped underground b nitrogen were trapped in rocks during extensive volcanic activity c phosphate gas were added to the atmosphere through erosion and evaporation. d sodium were used to form ancient fossils, seashells, and limestone

seismic wave -

an elastic wave in the earth produced by an earthquake or other means.

explanation:

since there isn't any suggested answers i will give you the reason and hopefully you can figure it

south africa, or rather all of africa, has not been in the location in which it is nowadays throughout the geological past. after the super-continent pangaea started to break apart, gondwanaland, in which was africa, moved further south, and parts of it came to be very close to the south pole. because the climate in this part of the world is very cold due to the very dispersed sun rays in there, what is now south africa, started to freeze, and the conditions were right for the formation of glaciers. the glaciers existed up until the period when gondwanaland started to break apart and what is now africa started to move towards north, sp it warmed up and the glaciers melted.