| A | B |
| paleontologist | A scientist who studies fossils to learn how organisms lived long ago. |
| scientific theory | A well tested concept that explains a wide range of observations. |
| evolution | The process by which living things have changed over time. |
| mold | A fossil formed when an organism buried in sediment dissolves, leaving a hollow area. |
| cast | A fossil that is a copy of an organism's shape. |
| potential energy | Energy that is stored and available to be used later. |
| kinetic energy | The energy an object has due to its motion. |
| energy | The ability to do work or cause chamge. |
| friction | The force that opposes the motion of one surface as it moves across another. |
| turbulence | A type of movement of water in which, rather than moving downstream, the water moves every which way. |