Answer:
Active.
Explanation:
First one must recognize the difference between active versus passive voice. Active voice is where the subject is put before the predicate, and passive is where the predicate ie put before the subject.
Example:
Sally drove her car. --> Active voice, because subject is first.
Subject predicate
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The car was driven by Sally --> Passive voice, because predicate is first.
predicate Subject
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Furthermore, you can break down the predicate into the object and action. Using the same example below...
Sally drove her car --> Active, because subject is first.
subject action object
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The car was driven by Sally--> Passive, because action and object are first.
Object action Subject
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In your example, your subject (Spectators) are first and your action and object (filled the stadium) are second. Therefore, it is active voice. (also, remember that your action and object can be combined to form the predicate.)
Hope this helps!
