If it doesn't matter who released the balloons, yes it can be passive. If it does matter who did the action, then the actor(s) should be named, making it an active voice sentence.
Passive:
The balloons were released at noon sharp and spectators gathered to watch the multicolored air show
Active:
Crews of tenth grade students released the balloons at noon sharp and spectators gathered to watch the multicolored air show.
Local politicians released the balloons at noon sharp and spectators gathered to watch the multicolored air show.
This use of passive voice is appropriate because the performer of the action is unimportant.
Collective nouns for people at a football match are a crowd of people, a stadium of people, and sometimes a mob of people. The people playing the match are a teams of players, or teams of footballers.
Scientific data must be gathered precisely using the appropriate method and tools necessary for each individual question to be answered
People at a concert are called several things:crowdaudienceconcertgoersfans
Scientific data must be gathered precisely using the appropriate method and tools necessary for each individual question to be answered.
what is gathered in synonym
"gathered" is already in the past tense, the present tense of "gathered" is "gather"
it is gathered from the biomolecules and molecule
i am not sure how it was gathered.
There is no verb in this sentence. There should be a verb after everyone eg Everyone sat around ....................... Everyone gathered around ..............
She gathered her courage before making the speech.
The present perfect tense of "gather" is "have gathered" or "has gathered."