What is referred to by 'cetacean correspondence'?

What is referred to by 'ceska republika'? What is referred to by 'cest la vie'? What is referred to by 'cest magnifique lemon rat'? Based on the clue 'cest tout the armistice ending la grande guerre w...', what is the answer? Which performer is associated with 'cetus'? Which performer is associated with 'ceylon'? Based on the clue 'cezanne said treat nature in terms of the cylinder...', what is the answer? What is associated with: cezanne used this style in the 1870s but found it mushy he wanted to make it solid and durable?