English for All

a person in the military who commands others; any person who is a member of a police force

a person with power in an organization; a representative of an organization or government; ad. of or about an office; approved by the government or someone in power

many times

a thick liquid that does not mix with water and that burns easily; a black liquid taken from the ground and used as fuel

not young or new; having lived or existed for many years

above and held up by; touching the upper surface of ("The book is on the table."); supported by ("He is on his feet."); about ("The report on the meeting is ready."); at the time of ("He left on Wednesday.")

one time only

being the single one or ones; no more than ("We have only two dollars.")

to start ("They opened talks."); ad. not closed; not secret

to do work or a job; to cut into the body for medical reasons