Open the brackets using correct verb form in Perfect Continuous Tenses

Людмила в категроии Английский язык, вопрос открыт 27.10.2017 в 11:59

1. The telephone (to ring) for 5 minutes, why don’t you answer it.
2. He (to teach) German for 2 years when I begin to teach English.
3. Tomorrow it will be a month as they (to work) on this project.
4. He (to come) here day after day for years.
5. At 8 in the morning we (to drive) for 6 hours.
6. By that time she (to study) already for 3 years.