Russian ⇄ Chinese English

по кочану stresses
avunc.	the answer's a lemon ('My Cumbrian grandmother when asked a question would reply, "The answer's a lemon". "Why?" we asked – "Suck it and see," was her response' – Janet C. Egan 2000). lingvo.ru Soulbringer); because the day of the week ends in “y” (Почему? – По кочану! – Why? – Because the day of the week ends in “y” Yanick); because the day of the week ends in "y" (Почему? – По кочану! – Why? – Because the day of the week ends in "y" Yanick)
inf.	just because (и т. п. Vadim Rouminsky); the answer is a lemon ("The answer is a lemon" means an unsatisfactory response – crosswordsolver.org)