Question

Fill in the blanks with the past perfect continuous tense of the given verbs.
1. She ____ (study) the behaviour of the animals for
many years.
2. Some scientists ____ (warn) about environmental
damage since the nuclear plant was set up.
3. We _____ (prepare) for the competition
throughout the past week.
4. She _____ (practise) for the auditions the
entire day.
5. He ____ (think) about his decision to change jobs.
6. The animals ____ (search) for a new home for a month.
7. The author _____ (write) her next novel for three years.
8. The notorious pirates ____ (give) the navy the slip for a decade.
9. The aliens ___ (visit) Earth for a century before people came to know of their existence.
10. The satellite _____ (orbit) the planet for fifteen years by the time it was de commissioned.​

Answer 1

Answer:

1. Studied

2. Warned

3. Prepared

4. Practiced

5. Thought

6. Searched

7. Wrote

8. Gave

9. Visited

10. Orbited

Answer 2

Answer:

1-had been studying

2-had been warning

3-had been preparing

4-had been practicing

5-had been thinking

6-had been searching

7-had been writing

8-had been giving

9-had been visiting

10-had been orbiting

past perfect continuous tense=had+been+present participle