Choose the correct options

1. No sooner was my school project finished [when|than|then] there was a power cut.
2. Hardly had we fallen asleep [when|than|then] the alarm clock rang.
3. Answer the riddle, and only [when|than|then] can you get the prize.
4. No sooner had Kate left [when|than|then] somebody called and asked for her.
5. Hardly had I come home [when|than|then] I felt extremely exhausted.
6. It was only [when|than|then] I realised that I missed her.
7. Scarcely had she arrived [when|than|then] the party finished.
8. No sooner do I think I'm done with homework [when|than|then] there's another task to be done.