Match the feature with its description a: stalactites 1: cave science b: stalagmites 2: tubes without hollow centers c: speleology 3: tubes with hollow centers d: speleothems 4: cave features answer

Features matched with its description 
A: stalactites      3: tubes with hollow centers 
B: stalagmites    2: tubes without hollow centers

C: speleology     1: cave science

D: speleothems 4: cave features

Speleology is shortly defined as the scientific study of caves. Speleothems are structures formed in a cave by the deposits of minerals from water dripping from the fractures of the ceiling of the cave. Most common types are the stalactites and stalagmites.

Stalactites began as a ring of crystals which later becomes small tubes with a hollow center. Stalagmites, on the other hand, are tubes formed without hollow centers. 

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The answer is letter c