What was one callenge workers faced while building the railroad?

As they built the railroad, the Union Pacific workers faced many struggles with the Native Americans. Bloody battles resulted from the railroad's appearance in these peoples lands. The Native Americans felt threatened by the "white man and his iron horse". However, they fought through and continued to build.

Explanation:

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.

the use of electrical signals that transit messages is know as