Question

why is still water an ideal environment for the formation of mold and cast fossils? soft tissue is preserved under sediment. hard tissue decays under sediment. sediment turns organisms into rock. sediment builds up over organisms.

Explanation:

Water allows sediment to build up over organisms. As sediment accumulates, it can create molds and casts of the organisms as the hard - parts are preserved and the soft - parts decay. The sediment eventually turns into rock, preserving the fossilized structures.

Answer:

Sediment builds up over organisms.