Is this sentence in the passive voice?

• An estimated 5000 primates are kept as pets in the UK.

is this sentence in the passive voice? If yes, how do I write it in active voice.

Is this a present passive voice? Is there such thing?

i have another question, the word ‘as’ here, is it a preposition or an adverb? if its an adverb, what type is it? – olivia just now Edit Delete