Hey there! :)
Answer:
1. How long has she been waiting for me?
2. How long have they been watching TV?
3. How long have they been walking in the park?
4. How long has she been cleaning the flat?
5. How long has he been doing his homework?
6. How long has he been having dinner?
7. How long have they been talking on the phone?
Hope this helps! :)
