Past Perfect Simple vagy Continuous?

Az alábbi párbeszédek mondataiban el kellet dönteni melyiket használjam, de nem vagyok biztos benne h jól csináltam (sőt, biztos h nem). Aki tud légyszi segítsen. :)

1. -Why was she exhausted?

- Well, she HAD BEEN STUDYING for hours.

2. - Why didn't he have anything to eat at the restaurant?

- He HAD ALREADY EATEN at home.

3. - HAD PETER FINISHED cleaning the pool when you arrived?

- No, he hadn't.

4. - Why did they give hime a promotion?

- He deserved it because he HAD BEEN WORKING hard all year.

5. -How long HAD THEY BEEN CYCLING before they stopped for a rest?

- For five hours.

6. - Did Frank graduate?

- No, he didn't. Although he HAD ALMOST COMPLETED his studies, he dropped out in the last term.

7. - What did you think of the modern art exhibition?

- It was fantastic! I HAD NEVER SEEN such beautiful works of art before.

Nagybetűvel azok vannak amik az én 'tippjeim'. Előre is köszönöm a segítséget. :)