Conditions affecting the hearing bones: otosclerosis. Otosclerosis is the most common cause of hearing loss in young people. It's a condition of abnormal bone growth affecting the stapes, the third of the three little bones in the middle ear.
Hydroelectric dams use water to produce electricity. Natural water resources include lakes, rivers, streams, ice pack, groundwater, precipitation and oceans. As global climate change begins to affect the distribution of water resources in the United States, water use in all sectors is coming under increasing scrutiny.
Lesson Summary. Natural resources are made by the Earth only, and they are useful to humans in many ways. They can be biotic, such as plants, animals, and fossil fuels; or they can be abiotic, meaning they originate from nonliving and inorganic materials.