17a== (8) I?T?R???. Difference in pitch betweeen two musical notes. 35a==(9) M??A??N?N. Hormone secreted by pineal gland that causes skin colour changes. 15d==(5) S???G Non standard form of language used to exclude others. 31d==(6) R??I?F. Method of carving etc in which design stands out from surface.