Complete the following sentences in the perfect continuous form of verb as mentioned in the brackets:

1. It ________ outside for half an hour. (hail)

2. I ________ for the bus since morning. (wait)

3. She ____________ hard since December. (study)

4. I ________ for this examination for one year. (prepare)

5. Tenzing _______ to climb Everest for many years before he succeeded in his mission (try)