Question

Раскройте скобки, используя Perfect Progressive:
1.I (to live) in St.Petersberg since 1990.
2.At last you have come. I (to wait) for half an hour.
3. He has been writing books since he was a yong man. He already (to write) eight books.
4. Today she has been helping her mother since morning. They already (to wash) the floor and (to dust) the furniture.
5. This is the factory where my father works. He (to work) here for fifteen years.

Answer 1

1.live
2wait
3write
4wash
5dust
6work

Answer 2

I have been living in St. Petersburg since 1990
At last you have come. I have been waiting for half an hour.
He has been writing books since he was a young man. He has already written eight books.
Today she has been helping her mother since morning. They have alredy washed the floor and dusted the furniture.
This is the factory where my father works.He has been working here for fifting years.
Подчеркнутые глаголы не Perfect Progressive, a просто Perfect.  В Perfect Progressive
нужен процесс и результат, а в Perfect просто результат.
Он уже написал восемь книг.
Они уже помыли пол и отполировавшими мебель.  И там и там просто результат.