How is a delta formed? a. a strong storm causes the sand to wash into the ocean. b. pollution causes deposits of sediment in the ocean. c. waves carry large deposits of sediments into the shoreline. d. streams slow down when they meet the ocean and deposit sediments

Which statements about wells are true? check all that apply. a) wells bring groundwater from the unsaturated zone to the surface of the water. b) wells need to be drilled below the water table. c) if water is pumped from a well too quicky, the well may run dry. d) water from wells is generally not safe to drink. e) water gushes from artesian wells due to pressure.

What evidence does the writer give to support his argument about coral reefs? a) he speaks of the activities of coral polyps. b) he describes the composition of the great barrier reef. c) he emphasizes the ways in which coral reefs are fragile. d) he points out the ways that scientists do research on the reefs.

Which of the following regions suffers the most from acid rain? a. the area around vancouver c. the area below atlanta b. the area below detroit d. the area above montreal