Q&A for speakers of other languages learning English
SELECT c.Id, c.postid, c.text, c.CreationDate FROM Comments c INNER JOIN ( SELECT Id, MAX(CreationDate) AS MaxCreationDate FROM Comments GROUP BY Id ) mc ON c.Id = mc.Id AND c.CreationDate = mc.MaxCreationDate where postid in (75632691, 76079476, 28645383) -- 75632691 -- 76079476 -- 28645383