Understanding that although the shape of an object may change, the mass of the object stays the same is an example of
a) object permanence.
b) a schema.
c) conservation.
d) accommodation.

30 a town is built on the banks of a small lake on the edge of a desert. after some time, the townspeople discover that water from the lake has become too polluted to use. describe one way that the lake may have been contaminated by the actions of the townspeople, and explain how the townspeople can remediate this problem.