Misc: What is a goup of clams?

Questions

"...do your -------------. You can't lead without knowing what you're talking about..."- George Bush (1925 - )?

"Working with ------------- is like getting hit over the head with a valentine."ZZZ- Christopher Plummer?

"...For that's the way it is with life, as some of the most beautiful days come completely by chance. But even the most beautiful days eventually have their ----------." - Author Unknown?

"--------------- is interest paid on trouble before it is due."- William Inge?

"------------ should merely indicate where the smiles have been."- Mark Twain (1835 - 1910)?