invaluable
[ɪnˈvæljʊəbl]adjective
invaluable (to sb/sthg) [experience, advice] inestimabile (per qn/qc)
[person, information] preziosissimo ( f preziosissima) (per qn/qc)
Complétez la séquence avec la proposition qui convient.
… this exercise, it's very easy.