This is the genetics: - H+ B5 r% ~1 r' _0 N- A5 C9 @ M# T
XY(man) x XX(woman) = / l& z' w8 Z# d; B5 e: U& a; rXX or XY, XX or XX, XY or XY. Some people have a twin. $ `" M2 s- p- g1 R 9 x& O8 `$ s" y& {/ y" wIf you really need a boy, you can ask a doctor to take your Y only and injiect into your wife's XX, then you will have boy only.$ U+ e" O5 T# t2 k. [' S
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Becareful, eating drug may cause mutation although the possibility is not so high.