For 37 years, Alex Trebek was a fixture on American TV as the host of “Jeopardy.” But the Canadian-born Trebek, the standard-bearer of a show known for its intellectual rigor, all-facts-with-a-touch-of-fun approach, got his start in news at the CBC and on a number of Canadian TV shows. Trebek died Sunday after a battle with pancreatic cancer. He was 80.