| A | B |
|---|
| rock | hard, naturally-formed minerals that make up the earth’s crust |
| geology | the scientific study of the origin, history, and structure of the earth |
| grains | small particles in rock |
| minerals | chemicals that make up rock |
| porous | having many small spaces (pores) that can hold a gas or liquid |
| *humus | organic material in soil made up of the decayed plants and animal |
| *inorganic | not made from something living or alive at one time |
| *interlocking | to fit together like the pieces of a jigsaw puzzle |
