| Heat and pressure are required to create ____ rocks. |
billion |
| The Earth was formed about 4.5 ____ years ago. |
lava |
| The molten rock below the Earth's surface is called ____. |
magma |
| Earthquakes create ____ waves, which are sound waves. |
metamorphic |
| The molten rock expelled by a volcano is called ____. |
million |
| Dinosaur fossils are found in some ____ rocks. |
organic |
| Amber, coral, pearl, and shell are ____ (unlike true minerals). |
sedimentary |
| Dinosaurs lived on the Earth from 230 to 65 ____ years ago. |
seismic |
