Complex sentence: Her first appearance as Mrs. Bellows wasn't seen until December 12 1966 in season 2 episode 14, when she was introduced to Tony and Roger by Dr. Bellows for the first time.
Split into simpler sentences: Her first appearance as Mrs Bellows wasn't seen until December 12 1966 in season 2 episode 14. When she was introduced to Tony and Roger by Dr. Bellows for the first time.