| New, crescent, quarter, ____, and full describe lunar phases. |
billion |
| Dinosaurs lived on the Earth from 230 to 65 ____ years ago. |
gibbous |
| Cooled lava and magma solidify to form ____ rocks. |
igneous |
| Heat and pressure are required to create ____ rocks. |
lava |
| Amber, coral, pearl, and shell are ____ (unlike true minerals). |
metamorphic |
| The molten rock expelled by a volcano is called ____. |
million |
| The Earth was formed about 4.5 ____ years ago. |
organic |
| Earthquakes create ____ waves, which are sound waves. |
seismic |
