1. Hoover Dam was built in the 1920s to _____.

a. create a tourist area for local boaters
b. stop water from flowing to Arizona and Nevada
c. provide more water to Arizona and Nevada
d. provide more homes for the animals

2. Hoover Dam was built across the _________ River.

a. Mead
b. Colorado
c. Mississippi
d. Ohio

3. What can protect the cities and farms that are located near water from flooding?

a. levees
b. dams
c. sand bags
d. windmills

4. What place holds more freshwater than any other place on Earth?

a. Lake Superior
b. Lake Mead
c. Colorado River
d. Great Lakes

5. Most of Earth's surface is covered by __________.

a. mountains
b. oceans
c. rivers
d. land