Answer:

1.) THEY RELEASE THEIR PRESSURES ON THE ROCKS DIRECTLY AND INDIRECTLY WHICH CAUSES THE ROCKS TO FRACTURE AND DISINTERGRATE.

2.) LIQUID WATER CAN SEEP INTO CRACKS AND CREVICES IN ROCK. WHEN ICE MELTS, LIQUID WATER PERFORMS THE ACT OF EROSION BY CARRYING AWAY THE TINY ROCK FRAGMENTS LOST IN THE SPLIT.

3.) CHANGES IN TEMPERATURE CAUSE ROCK TO EXPAND (WTH HEAT) AND CONTRACT (WTH COLD).

4.) THE SEED OF A TREE MAY SPROUT IN SOIL THAT HAS COLLECTED IN A CRACKED ROCK. AS THE ROOTS GROW, THEY WIDEN THE CRACKS, EVENTUALLY BREAKING THE ROCK INTO PIECES.

5.) ANIMALS CAN WALK ON ROCK OR DISTURB IT, CAUSING LANDSLIDES THAT SCRAPE OR SMOOTH ROCK SURFACES.

6.) BURNING COAL, NATURAL GAS, AND PETROLEUM RELEASES CHEMICALS SUCH AS NITROGEN OXIDE AND SULFUR DIOXIDE INTO THE ATMOSPHERE.