Ответ:
1. I have lost my key.
2. I have been reading the book you gave me, but i haven`t finished it yet.
3. I haven`t waited long
4. I have been cleaning the windows. So far I`ve cleaned five of them. There are only two more to do.
5. There`s a strange smell in here. Have you been cooking something?
Exercise 2
1. John`s terribly upset. He has broken off.. Apparently, she has been seeing someone else
2. Have you done an accident?
3. Have you been learning it for long?
4. He has failed that exam. He haven`t been studying hard recently
5. Has Sean Had been late
6. It has been sitting
7. I have been doing grammar exercise all morning.