Question

Choose the correct form of the verb to fill in the following blank:
Lisa ___________ her homework for two hours before her friends visited her.

• A. was doing
• B. had been doing
• C. had done
• D. was done

Answer 1

The correct option is B had been doing

Here, 'had been doing' in Past Perfect Continuous Tense is correct because it is used to indicate an action in the past that began before a certain point in the past and continued up untill that time. Here, 'for two hours ..' indicates an action in the past that began before a certain point in the past.
'Was doing' in past continuous is incorrect because it is used to indicate uncompleted action in the past (with or without time reference).
'Had done' in past perfect is incorrect it is used to indicate a completed action of the past that happened before another event took place.
'Was done' in simple past is incorrect because it indicates an action that has already been completed.