11 We were travelling when we got( received ) a letter from our parents.
12 We were doing shopping when we saw him .
13 Where were you at 12 o’clock? I was at the institute.I was having classes at this time.
14 He entered the room and saw that his father was reading a book.
15 Were you translating an article or preparing for a test at 2 o’clock?I was preparing for a test.
16 When I approached him,he was sunbathing.
17 We were speaking about him when he entered.
18 Were you having breakfast when I rang you up? Yes,I was.
19 I didn’t make notes when he was lecturing.
20 Were you watching TV or listening to music while I was having dinner? I was listening to music.