Limestone+Caves



 Limestone Caves

1. Limestone Caves can be spectacular structures filled with giant stalactites and stalagmites. These caves are formed when rainwater, which is a weak acid, dissolves calcite, or lime, out of limestone. Over time, the lime-laden water drips down into cracks enlarging them into caves. Some of the lime is then re-deposited to form stalactites and stalagmites.  2. Stalactites, which grow down from cave ceilings, are formed in limestone caves when groundwater containing dissolved lime drips from the roof of the cave and leaves a thin deposit as it evaporates. Stalactites generally grow only a fraction of an inch each year, but over time a considerable number may grow to be several yards long. In cases where the supply of water is seasonal, they may actually have growth rings resembling those on tree trunks that indicate how old the stalactites are.

3. Stalactites are formed on the floor of a limestone cave where water containing dissolved lime has dripped either from the cave ceiling or form a stalactite above. They develop in the same way as stalactites, when water containing dissolved limestone evaporates. In some caves with mature limestone development, stalactites and stalagmites grow together, creating limestone pillars that stretch from the cave floor to the cave ceiling.

6. It is indicated in paragraph one, that all of the following are part of the process of forming limestone caves EXCEPT that A rainwater dissolves lime from limestone B the lime-filled water seeps into breaks in the ground C the lime in the water evaporates D the cracks in the ground develop into caves

7. According to paragraph 2, it is not true that stalactites A enlarge cave ceilings B are found in limestone caves C grow in downward direction D grow quite slowly

8. It is not mentioned in paragraph 2 A how long stalactites may grow <span style="font-family: Helvetica,sans-serif; font-size: 12pt;">B how the age of a stalactite is determined <span style="font-family: Helvetica,sans-serif; font-size: 12pt;">C what one of the effects of a limited water supply is <span style="font-family: Helvetica,sans-serif; font-size: 12pt;">D what causes stalactites to disappear

<span style="font-family: Helvetica,sans-serif; font-size: 12pt;">9. According to paragraph 3, stalagmites are not formed <span style="font-family: Helvetica,sans-serif; font-size: 12pt;">A on cave floors <span style="font-family: Helvetica,sans-serif; font-size: 12pt;">B from lime dissolved in water <span style="font-family: Helvetica,sans-serif; font-size: 12pt;">C above stalactites <span style="font-family: Helvetica,sans-serif; font-size: 12pt;">D as water containing lime evaporates

<span style="font-family: Helvetica,sans-serif; font-size: 12pt;">10. It is not indicated in paragraph 3 that limestone pillars <span style="font-family: Helvetica,sans-serif; font-size: 12pt;">A result when a stalactite and a stalagmite grow together <span style="font-family: Helvetica,sans-serif; font-size: 12pt;">B are attached to both the floor and the ceiling of a cave <span style="font-family: Helvetica,sans-serif; font-size: 12pt;">C are relatively aged limestone formations <span style="font-family: Helvetica,sans-serif; font-size: 12pt;">D are more durable than stalactites and stalagmites

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