To keep out dirt and other bad things
An example of a career is that of a geologist. It involves studying the earth in all its manifestations right from the study of the 3 main rock types, of ore deposits, of oil and gas deposits, of fossils and minerals, of the earth's structure, its' landforms, etc. The types of work it involves are such as mineral exploration geologist, mine geologist, geotechnical engineer, paleontologist, petroleum geologist, structural geologist to name some of the types of work.
The answer is: [C]: peptides .
_________________________________________________________
I can't remember the branch, I literally just took psych last year too, but perspective would be because some people have outside influences affecting the parts of the brain that can trigger depression; sadness .
