leaching. Phosphate leached from guano phosphatizes the underlying rocks in some areas, forming apatite where the host rock is limestone and forming aluminum- or aluminum-iron-phosphate minerals where the underlying rock is a silicate. Individual deposits of both igneous apatite and marine phosÂ­
Medicare Part B (Medical Insurance) covers diagnostic hearing and balance exams if your doctor or other health care provider orders these tests to see if you need medical treatment. Medicare doesn't cover routine hearing exams, hearing aids, or exams for fitting hearing aids.
Part A is hospital insurance. Most people do not have to pay for Part A. Part B is medical insurance. Most people pay monthly for Part B. Click here for Medicare Premiums for Part A & Part B. (This information is provided by the Center of Medicare & Medicaid Studies.)