Present Perfect. Change the sentences to negative.

1. He has exercised this week.

2. It has been easy.

3. She has been sick lately.

4. We have known each other for a long time.

5. I have called her today.

6. He has failed to get their attention.

7. I have tried to reach him.

8. She has put on a black dress.

9. We have worked on this together.

10. They have missed their chance.