1. Which gas is a source of natural groundwater pollution?
A. Carbon
B. Oxygen
C. Hydrogen
D. Radon
D?
4. A stream channel is formed when water
A. carves a very deep and wide channel into rock.
B. carries minerals into the ocean.
C. creates a depression, which forms a lake.
D. carves a narrow path into rock.
D?
5. How many chemical reactions are possible regarding the formation of carbonic acid and the dissolving of calcite?
A. 3
B. 10
C. 23
D. 2
A?
1 answer
how fast are a hurricanes winds?