1.Are you translating a text from a textbook?
What are you translating?
Are you translating a text from a textbook or newspaper?
.Are you translating a text from a textbook, aren't you?
2.Are they playing games?
What are they doing now?
Are they playing games or reading book?
Are they playing games, aren't they?
3.Has he been drinking juice since childhood?
What has he been drinking since chilhood?
Has he been drinking juice or eating cake since childhood?
He has been drinking juice since childhood, has't he?