What is referred to by 'a topic or motif'?

What is associated with: a top seller in 1749 weve been fielding responses on this book since our first season? What is associated with: a top sport in the country uruguay has won the world cup in this twice in 1930 1950? Based on the clue 'a top ten hit twice rhapsody', what is the answer? Based on the clue 'a topee is also called this kind of helmet from th...', what is the answer? Based on the clue 'a torchiere is a standing one of these that often ...', what is the answer? Based on the clue 'a tormentor is a side curtain in a theater to prev...', what is the answer? Based on the clue 'a tornado is typically a tube or this shaped cl...', what is the answer? Based on the clue 'a tornado that forms over a lake or ocean', what is the answer?