Past Perfect Tense vs Past Continuous Tense

I ....about that book until you mentioned it.

• hadn't heard
• hadn't been hearing

......we booked our tickets, we had searched for the hotels.

• after
• before

Once Sally saw me , I .......for 3 hours.

• had gardened
• had been gardening

We use Past Perfect for an action which happened before another past action or before a stated time in the past.

• Yes
• No

Chuck had left the house before I  ________________(CALL).

• called
• had called

By the time his friend _____ the conclusions, Luke ______ all the assignment. 

• finished   /   had already sent
• sent  /  had already finished
• had send   /   finished

The children were wet because they (play) football in the rain.

• had played

• had been playing

We were very hungry because we (not / eat).

• had not eaten

• had been eating

I was delighted when I found my keys.

I( look) for them for hours.

• had been looking

• had looked

She was exhausted because she (work) since eight o'clock that morning.

• had worked

• had been working