How does water form caves or caverns?

Caves are formed by the dissolution of limestone. Rainwater picks up carbon dioxide from the air and as it percolates through the soil, which turns into a weak acid. This slowly dissolves out the limestone along the joints, bedding planes and fractures, some of which become enlarged enough to form caves.

Explanation:

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explanation:

health care plans in the united states having high costs because they are focusing on providing quality programs for different groups of individuals. the quality of the service is based on money flow received from the members. without this investment, couldn't be possible a constant scientific searching to prevent death and illness caused because of low levels of health investigation. currently, the complaints are not about the highest cost, but about the coverage and benefits to access the necessary health services required by the members.  

besides, if a global health system is established the quality levels will fall down because of the standardized of the health. the access to care will increase but the quality will be low because it depends on the money invested.