Ex.2
1. My sister has been here since 12 o'clock.
2. This dog has lived on the streets for months.
3. Her brother has travelled to Japan many times.
4. My sisters and I have watched this film many times.
5. His friends have eaten a purple carrot.
Ex.3
1. My sister hasn't been here since 12 o'clock.
2. This dog hasn't lived on the streets for months.
3. Her brother hasn't travelled to Japan many times.
4. My sisters and I haven't watched this film many times.
5. His friends haven't eaten a purple carrot.
