"We will be part of that."
Translation:Nós vamos fazer parte daquilo.
Duolingo needs to start teachin fixed phrases. There is no way I could have figured this out based on what I have learned in Duolingo so far.
Why ser parte and not estar parte? Without context there is no indication of pernanence.
That's because there isn't this "word combination" here. Hope I've helped! ;)