The only correct statement concerning reference is:

Próximas questões
Com base no mesmo assunto
Q1837 Inglês
The oil and natural gas industry has developed and
applied an impressive array of innovative technologies to
improve productivity and efficiency, while yielding
environmental benefits. According to the U.S. Department
of Energy, "the petroleum business has transformed itself
into a high-technology industry."
State-of-the-art technology allows the industry to
produce more oil and natural gas from more remote
places - some previously unreachable - with significantly
less adverse effect on the environment. Among the
benefits: increased supply to meet the world's growing
energy demand, reduced energy consumption at oil and
natural gas facilities and refineries, reduced noise from
operations, decreased size of facilities, reduced
emissions of pollutants, better protection of water
resources, and preservation of habitats and wildlife.
With advanced exploration and production
technologies, the oil and gas industry can pinpoint
resources more accurately, extract them more efficiently
and with less surface disturbance, minimize associated
wastes, and, ultimately, restore sites to original or better
condition.
Exploration and production advances include
advanced directional drilling, slimhole drilling, and 3-D
seismic technology. Other segments of the industry have
benefited from technological advances as well. Refineries
are becoming highly automated with integrated process
and energy system controls; this results in improved
operational and environmental performance and enables
refineries to run harder and produce more products safer
than ever before. Also, new process equipment and
catalyst technology advances have been made very
recently to meet new fuel regulations requiring very low
levels of sulfur in gasoline and diesel.
Technology advances such as these are making it
possible for the oil and natural gas industry to grow in
tandem with the nation's energy needs while maintaining
a cleaner environment. The industry is committed to
investing in advanced technologies that will continue to
provide affordable and reliable energy to support our
current quality of life, and expand our economic horizons.
For example, we are researching fuel cells that may
power the vehicles of tomorrow with greater efficiency
and less environmental impact. We are investigating ways
to tap the huge natural gas resources locked in gas
hydrates. Gas hydrates are common in sediments in
the ocean's deep waters where cold temperatures and
high pressures cause natural gas and water to freeze
together, forming solid gas hydrates. Gas hydrates could
be an important future source of natural gas for our nation.
Some of our companies are also investigating
renewable energy resources such as solar, wind,
biomass and geothermal energy. By conducting research
into overcoming the many technological hurdles that limit
these energy resources, they hope to make them more
reliable, affordable and convenient for future use. Although
the potential for these energy resources is great,
scientists do not expect them to be a significant part of
the nation's energy mix for many decades. For this
reason, the industry must continue to invest in
conventional resources such as oil and natural gas. We
will need to rely on these important energy resources for
many decades to come.

In: http://api-ec.api.org/focus/index
The only correct statement concerning reference is:
Alternativas