doctorate

do, study for, take, write

He is studying for a doctorate in environmental science at the university.

complete

She finally completed her doctorate in marine biology after five years of research.

have

My professor has a doctorate in chemistry from Oxford University.

~ from

She earned her doctorate from a prestigious medical school in London.

~ in

She earned her doctorate in Environmental Science after five years of research.

~ of

She earned a doctorate of philosophy in environmental science after five years of research.

~ on

She completed her doctorate on renewable energy systems after five years of research.