Question

select the word that means an open or available position. representatives in the united states congress are elected for two - year terms. sometimes, though, a vacancy occurs before the term ends. the only way to fill it is by holding a special election.

Explanation:

The text defines the word "vacancy" as an open or available position in the context of United States Congress terms. When a vacancy occurs before the term ends, a special election is held to fill it.

Answer:

vacancy