What is an estuary?
Awhere a freshwater river runs into an extension of the ocean
Bwhere a freshwater river runs into an extension of a lake
Cwhere a freshwater river runs into land
Dwhere a freshwater river runs into another river
Awhere a freshwater river runs into an extension of the ocean
Bwhere a freshwater river runs into an extension of a lake
Cwhere a freshwater river runs into land
Dwhere a freshwater river runs into another river