Question

is this it is in active voice or passive voice dairy products were consumed by north Africans as early as 7000 years ago

Answer 1

"dairy products were consumed by north Africans as early as 7000 years ago"

This is a passive sentence with simple past tense.
(formula → O + was / were + Verb 3)

If you want to change it to active voice, then use this formula for active simple past tense
✐ S + Verb 2 + O

So the active voice is :

"North Africans consumed dairy products as early as 7000 years ago"
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Subject : English
Keywords : Passive voice, simple past, active voice

Answer 2

This sentence is currently in the passive voice.

We can tell this because it's saying dairy products WERE CONSUMED. The use of the being verb (were) indicates the passive voice.

To change this to active voice, the being verb needs to be eliminated. It is helpful to make the one who is doing the action come at the beginning of the sentence.

North Africans consumed dairy products as early as 7000 years ago -- that is now in the active voice.