A geographer who studies the similarities between two places most often uses which of the six essential elements of geography?
A. the world in spatial terms
B. places and regions
C. physical systems
D. environment and society
Please select the best answer from the choices provided
A
B
С
D

Just do the math, then think

Where are the colloms

Answer is b)eutrophication occurs when excess nutrients are present in aquatic ecosystems, resulting in the increased production of plant life and the subsequent decrease in the oxygen levels of the watereutrophication occurs when there are excess nutrients in a body of water. this results in plants having more food and reproducing  more, sometimes leading to more aquatic animal life as well. ultimately, this can reduce the oxygen level in the ecosystem. 

Hanging valley i would think so..