Слово "necessary". Англо-русский словарь Мюллера

She was in fact a woman of forty (a charming age, but not one that excites a sudden and devastating passion at first sight), and she gave me the impression of having more teeth, white and large and even, than were necessary for any practical purpose.

It was necessary.

'For instance, Ivan,' Berlioz was saying, `you portrayed the birth of Jesus, the son of God, very well and satirically, but the gist of it is that a whole series of sons of God were born before Jesus, like, say, the Phoenician Adonis, [15] the Phrygian Atris, [16] the Persian Mithras. [17] And, to put it briefly, not one of them was born or ever existed, Jesus included, and what's necessary is that, instead of portraying his birth or, suppose, the coming of the Magi,'[18] you portray the absurd rumours of their coming. Otherwise it follows from your story that he really was born! ...'

Remember, the firemen are rarely necessary.

"These power objects are necessary only when a man does not have an ally.

All the students, lay and clerical, were very poorly provided with means for procuring themselves necessary subsistence, but at the same time very fond of eating; so that, however much food was given to them, they were never satisfied, and the gifts bestowed by rich landowners were never adequate for their needs.