Of which; alternative to inanimate sense of “whose”.(pronoun)
Contraction of which is(phrase)
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Use "which's" in a sentence
"Hillary used methodist middlenme which's more normal."
"Anyway, it's nice to see New Labour finally being killed off like some sort of rabid, three-legged dog which's bitten loads of killed and raped at least one old lady's leg."
"But for a guy like me who plan to make a short visit to Taiwan one day, which's just a matter of time, your blog is at a little high level."