Supplements as generally understood include vitamins, minerals, fiber, fatty acids, or amino acids, among other substances. U.S. authorities define dietary supplements as foods, while elsewhere they may be classified as drugs or other products. There are more than 50,000 dietary supplements available. More than half of the U.S. adult population (53% - 55%) consume dietary supplements with most common ones being multivitamins.
Wind power capacity has expanded to 369,553 MW by December 2014, and total wind energy production is growing rapidly and has reached around 4% of worldwide electricity usage.
A) Wind is the most commonly used renewable energy source in the United States. B) Hydropower uses the kinetic energy of water to generate electricity. C) Wind energy does not use a turbine or a generator to produce electricity. D) Solar energy can only be used on Earth. It can't be used in space.