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.
Natural resources are things that occur naturally, and that are useful to us. They include fuels such as oil and natural gas, and materials such as iron ore, and timber. Renewable resources are those that are replaced in nature at a rate close to their rate of use e.g. plants, forests and animals. Care is needed to make sure resources are used sustainably and not over- harvested.