adj.
VERBS
▪ be , prove
▪ become
▪ make sb/sth
▪
He had soon made himself ~.
▪ consider sb/sth
ADVERB
▪ absolutely
PREPOSITION
▪ for
▪
Written sources are considered absolutely ~ for today's history teaching.
▪ in
▪
These drugs are almost ~ in the fight against the disease.
▪ to
▪
skills which turned out to be ~ to her career
Indispensable is used with these nouns: ↑ prerequisite , ↑ tool