Author Question: Watersheds are surrounded by A) fluvial units. B) continental divides. C) hydrologic unit codes ... (Read 41 times)

karen · **on:** Jul 14, 2018

Watersheds are surrounded by

A) fluvial units.
B) continental divides.
C) hydrologic unit codes (HUCs).
D) stream orders.
E) drainage divides.

Question 2

According to readings from the Mauna Loa Observatory, CO2 concentrations in May 2013 exceeded ________ for the first time during the last 800,000 years.

A) 100-ppm B) 200-ppm C) 300-ppm D) 400-ppm E) 500-ppm