He has been talking for 2 years about his trip to Australia.
He has been looking for his book all the morning.
I have been wondering if i couldn't study German a little more.
He has been thinking about his girlfriend all the week.
We have been just talking about you.
I have been writing for you for about thirty minutes.
He has been sitting in that chair all the evening.
We have been traveling though Texas for 4 years.
We have been listening to the radio all the morning.
(?) have/has been waiting for the bus for half an hour.
Объяснение:
В последнем, т.к. вы не написали существительное в начале, я написала два варианта have/has. Если там было he/she/it то выберите has
