Câu trả lời:
A: What were you doing at this time yesterday?
Past continuous:
Thể khẳng định (Affirmative form)
I/He/She/It + was +verb-ing We/ You/ They + were +verb-ingThể phủ định (Negative form)
Subject + was/were + not + verb-ingThể nghi vấn (Interrogative form)
Was/Were + subject + verb-ing?