If the interacting entities are not persons, we have "it" as a neuter pronoun. If they are persons, we can use "he" and "she" alternately, "he/she" (somewhat cu

If the interacting entities are not persons, we have "it" as a neuter pronoun. If they are persons, we can use "he" and "she" alternately, "he/she" (somewhat cumbersome and stilted), or "they".