Ask a disjunctive and a general question. make the same sentence negative 1. they noticed some change in the weather. 2. i have promised good to the industrious students. 3. there is an invitation to the exhibition on your desk. 4. they will join their group in a moment

1. They noticed some change in the weather.
General question - Did they notice any change in the weather?
Disjunctive question - They noticed some change in the weather, didn't they?
Negative - They didn't notice any change in the weather. 

2. I have promised good to the industrious students.
General question - Have I promised good to the industrious students?
Disjunctive question - I have promised good to the industrious students, haven't I?
Negative - I haven't promised good to the industrious students.

3. There is an invitation to the Exhibition on your desk.
General question - Is there an invitation to the Exhibition on your desk?
Disjunctive question - There is an invitation to the Exhibition on your desk, isn't there?
Negative - There is no invitation to the Exhibition on your desk. / There isn't any invitation to the Exhibition on your desk.

4. They will join their group in a moment.
General question - Will they join their group in a moment?
Disjunctive question - They will join their group in a moment, won't they?
Negative - They won't join their group in a moment.