Ответы:

1. Jim has been digging the garden since early this morning.

2. You've been watching TV since you got up.

3. Judith has* twisted her ankle and is in great pain.

("has" не используется в речи и считается формально, в простой речи просто было бы "Judith twisted")

4. I've been trying to contact him for weeks.

5. The storm is so violent that the authorities have declared a state of emergency.

6. Mila started a diet last month and has lost two kilos so far.

7. The forest fire has been burning for two days.

8. Have you heard any news about the trapped miners?

9. I've just made some tea.

10. The town has never experienced such terrible floods before.