A landscape that is characterized by numerous caves, sinkholes, fissures, and underground streams, due to its calcareous bed rock, (CaCO3), which is highly soluble in water.
A species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically.
The moral virtue of compassion and assistance to others.
The energy an object possesses due to its motion.
A colorless, odorless element that is a noble gas (elements occurring in gaseous form that do not react chemically with other elements or chemical compounds except very rarely). It is used in certain fluorescent lamps and photographic flash lamps.