A gardener finds many plants with leaves similar to this growing in the garden. The plants are healthy, vigorous, and unexpected, as the gardener did not plant them in the garden. The gardener has to decide whether to destroy the plants, transplant them somewhere else, or keep them where they are.

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.