Final answer:
The sentence 'The store was robbed just after midnight' is already in active voice with an implicit subject performing the action. Rewriting it in passive voice would change the sentence to focus on the action being done to the store, which is unnecessary since the original sentence is appropriately active and clear.
Step-by-step explanation:
The sentence you're asking about, 'The store was robbed just after midnight,' is indeed already in the active voice. In active voice sentences, the subject performs the action stated by the verb. For example, 'The police arrested the thief,' shows the police (the subject) doing the action of arresting. The sentence you provided does not need to be rewritten in active voice because it is already constructed that way. However, if we were to create a passive voice version, it could read, 'The store was robbed just after midnight' where the store becomes the subject that the action is being done to. When considering wording and sentence structure, it's essential to choose constructions that convey the intended meaning clearly and effectively.