Complex sentence: He twice served as a member of the Presidency of the Seventy, in 1978 to 1980 and from 1985 to 1989, at which time he was given general authority emeritus status and released from active duties.
Split into simpler sentences: He twice served as a member of the Presidency of the Seventy, in 1978 to 1980 and from 1985 to 1989. In 1989, he was given general authority emeritus status and released from active duties.