What is associated with: 2 of the most performed songs in the us after happy birthday both were sung march 31 2008 at dodger stadium?

Based on the clue '2 of the main types of these are the cycloid ones ...', what is the answer? What is associated with: 2 of the men used as models for this 1913 us coin were named john big tail crow tails? What is associated with: 2 of the model numbers for these big screen robots are the t 800 the t 1000? Based on the clue '2 of the more than 800 languages spoken on this co...', what is the answer? Based on the clue '2 of the movie roles shes played are ethel thayer ...', what is the answer? Based on the clue '2 of the ores for this yellowish green gas are roc...', what is the answer? Based on the clue '2 of the people who witnessed his execution were j...', what is the answer? Based on the clue '2 of the rude mechanicals from this play are tom s...', what is the answer?