"They support both children."
Translation:Wspierają oboje dzieci.
"Oba" is used for neuter (most of them, but not here) and masculine non-personal nouns. "Obaj" for masculine personal. "Obie" for feminine. And "oboje" before nouns denoting people of mixed sex, personal and animate neuter nouns (of which there are few), and non-masculine personal pluralia tanta.
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