1. At this time yesterday we (play) were playing tennis in the schoolyard.

2. At 7:00 pm yesterday i (watch) was watching  TV.

3. Yesterday while my father (watch) was watching TV, my mother (read) was reading the newspaper, my sister (do) was doing her homework and I (play) was playing chess with my friend.

4. What were you doing when I phoned you? I (have) was having a bath.

5. She (do) was doing her homework at the time yesterday.

6. Mary (water) was watering the flowers at 3:00 p.m yesterday.

1. were playing

DHNB: At the time yesterday --> Thì quá khứ tiếp diễn

2. was watching

DHNB: at 7.p.m yesterday --> Thì quá khứ tiếp diễn

3. was watching/ was reading/ was doing/ was playing

4. was having

DHNB: were you doing --> Quá khứ tiếp diễn

5. was doing

DHNB: at the time yesterday --> Thì quá khứ tiếp diễn

6. was watering

DHNB: at 3.p.m yesterday --> Thì quá khứ tiếp diễn