Si2C19
What is this compound

This statement about matter and its behavior is best classified as a

Astream of surface water reaches a porous portion of sediment and seeps into the ground. this water eventually joins a large reservoir of water located beneath the earth's surface. the example above describes the interacting with the a. cryosphere; biosphere b. hydrosphere; biosphere c. hydrosphere; geosphere d. cryosphere; geosphere

Just on number 2 (all parts), and if you do answer explain in detail