Conversation so far:
What did Stephen Hillenburg start Stephen Hillenburg's career in?
park service attendant in Utah and an art director in San Francisco, before landing the job he wanted: teaching children.
What subject did he teach when he became a teacher?
marine-biology teacher.

Question: Did he teach any other subjects alone the years?
Self-contained rewrite: Did Stephen Hillenburg teach any subjects besides marine biology alone the years?