2. By 6 o'clock yesterday Lolly (to come) back from the skating rink and at 8 o'clock she (to do) her homework.

Solution:

• 2. By 6 o'clock yesterday Lolly had come back from the skating rink and at 8 o'clock she was doing her homework.

Explanation: Lolly coming back from the skating rink is a completed action before 8 o'clock, hence Past Perfect. Her doing homework was in progress at 8 o'clock, hence Past Progressive.