Why do shallow estuary waters create unique habitats for organisms living here?

Consider the last statement in the prompt: "people take such environmental factors into account in their choices when deciding where to live." do all people have a choice as to where they live? what factor plays a key role in this decision and may therefore play a large role in determining quality of life?

The process by which natural forces move weathered rock and soil brim one place to another is called

Which codon is the code for the amino acid histidine (his)?