Lakes are formed by precipitation and runoff, and the Caspian Sea is, strictly speaking, not really a sea but instead the world's largest lake. Given these facts, what was formed by precipitation and runoff among the following options:
- a hydraulic system
 - streams.
 - The Caspian Sea
 - kalenchoes
 - near the shoreline
 - swamp vegetation
 - Calcium carbonate
 - patch reefs


 

   The Caspian Sea      