1)They doesn't discuss many questions after work.
Does they discuss many questions after work?
Does they discuss many questions after work or not?
They discuss many questions after work,doesn't they?
What they discuss after work?
(Они обсуждают множество вопросов после работы)
2)The engineers didn't work in Moscow two years ago.
Did the engineers work in Moscow two years ago?
Did the engineers work in Moscow two years ago or not?
Where did the engineers work two years ago?
The engineers work in Moscow two years ago,didn't they?
(Инженеры работали в Москве два года назад)
3)She won't finish this work in a week.
Will she finish this work in a week?
Will she finish this work in a week or not?
When will she finish this work?
She'll finish this work in a week,won't she?
(Она завершит эту работу через неделю)