Is there any pollution in river yenisei?

What is an example of a deep current? What are some physical and chemical weathering on the leaning tower of Pisa? What are the advantages in living in a big city like Tokyo? What do tributaries increase the economic benefits of rivers? How will the three gorge dam reduce flooding? Who built the st lawrance seaway? What can warm currents do to some areas that are normally colder? Why it is called Bermuda triangle not Miami triangle? How big can waves get and how does it impact sea life? How many workers is did it take to build Burj Khalifa? How many gallons of fuel were remaining when the Spirit of St. Louis landed in France? Why do hikers owe a debt of gratitude to Appalachian Trail club members? What is the benefits of tourism to a country? Which province borders the great lakes? Why is so little known about the early life of people in the Indus River and Huang Ho valleys? How deep are the mersey tunnels below the surface of the river mersey? How long does it take to travel the Erie Canal? How do you unlock the forest in happy street? Where is Independence Rock located? Can South Koreans visit North Korea?