Образуйте от данных слов антонимы при отрицательных префиксов: In-: significance, separable, official, subordinate, sufferable, urban(e), appropriate, supportable, dependence, dependant.
Un-: limited, steady, suitable, known, reasonable, thinking, trained, suspected.
insignificance, inseparable, unofficial, insubordinate, insufferable, non-urban, inappropriate, unsupportable, independence, independent.
unlimited, unsteady, unsuitable, unknown, unreasonable, non-thinking, untrained, unsuspected.