Aperson coughs when a foreign object is in the windpipe. the velocity of the cough depends on the size of the object. supppose a person has a windpipe with a 20-mm radius. if a foreign object has a radius r, in millimeters, then the velocity v, in millimeters/second, needed to remove the object by a cough is given by:

there are no options provided but you can choose among the following gender-neutral pronouns: zir, hir, eir, vis, tem, eir.

in the normal course of maintaining a pronoun-antecedent agreement, we could have used the words his or her but since we are also required to use gender-neutral language, we need to replace it with its equivalent gender-neutral pronoun.