What is referred to by 'cest magnifique lemon rat'?

Based on the clue 'cesium rubidium were discovered by gustav kirchho...', what is the answer? Based on the clue 'cesium was the first element found by this process...', what is the answer? What is referred to by 'ceska republika'? What is referred to by 'cest la vie'? Based on the clue 'cest tout the armistice ending la grande guerre w...', what is the answer? What is referred to by 'cetacean correspondence'? Which performer is associated with 'cetus'? Which performer is associated with 'ceylon'?