Read the introduction and first paragraph of an essay about energy sources. (1) The nation's energy use iS largely dependent on fossil fuels. (2) These fuels are nonrenewable
resources, and they cause pollution. (3) We cannot
continue our reliance on a fuel that will eventually run
out. (4) Thus, we must find other ways to sustain our energy demands. (5) Pursuing alternative fuel sources
is the key to solving our energy crisis.
(6) Currently, about 1 percent of energy in the United States is produced by the sun, and solar energy has
the potential to become a more widely used energy source. (7) Through different technologies, such as
solar cells, scientists have learned to use the sun's radiation to create electricity. (8) Solar energy is both
inexhaustible and clean. (9) The major limit to this alternative source is that equipment is expensive. (10)
Developing a cost-effective way to harness the power of the sun will be a significant development in
solving our energy crisis.
Which sentence is the author's thesis statement?