Examples:
cartography
card
archaeology
archetype
monarchy
legal
loyal
purse
personal
cinema
kinase
car
carpenter
hippopotamus
Mesopotamia
dative
data
date
...
Proto-Slavic
*pro
→
Old Church Slavonic
про-
(inherited)
→
Russian
про
(inherited)
→
Albanian
prek
(mention)
→
Ukrainian
про
(inherited)