1. manganese is a strategic mineral. in other words,
a. nations that want manganese must import it
b. world demand for manganese is greater than world supply
c. supplies of this mineral are unknown in quantity and location
d. manganese is a crucial element in weapons manufacturing

2. which of the following energy sources is most available at the edges of tectonic plates?
a. natural gas
b. geothermal
c. winds
d. tides