She wasn't reading an interesting book from 4 till 6.
Was she reading ...?
Who was reading ...?
When was she reading a book?
What was she reading from 4 till 6?
Was she reading a book or a magazine ?
She was reading a book,wasn't she?
We weren't writing a letter at 2 o'clock
last Sunday.
Who was writing...?
What were we writing at 2 o'clock
last Sunday?
When were we writing a letter?
Were we writing a letter...?
We were writing a letter,weren't we?
Were we writing a letter or an article ?