N ---> D

How is explainable such sound changes like N -> D in Baltic
languages?
For. ex:
(Slavic) Neb-, (Sanskrit) Nabh- ----> Baltic Deb- (Debesis - cloud,
Debess - the sky)

(Old Prussian) newints, (Latin) nov- ---> Lith. devintas
also Latin un|devi|ginti (nineteen)...

So?