Based on the clue 'a 3 legged stand on which to rest your portable me...', what is the answer?

Based on the clue 'a 250 million year old grayish white limestone lay...', what is the answer? Based on the clue 'a 25th anniversary is a silver this', what is the answer? Based on the clue 'a 2nd verse to this rhyme begins every fiddler he ...', what is the answer? What is associated with: a 3 cent stamp of 1956 honored the 50th anniversary of this wyoming national monument? What is associated with: a 3 letter exclamation of surprise or the band from norway that hit no 1 with take on me in 19… Based on the clue 'a 3 letter suffix that forms the present participl...', what is the answer? Based on the clue 'a 3 letter word for to veto or a german water spri...', what is the answer? What is referred to by 'a 3 minute egg'?