Ответ:

1. We have known each other for 5 years.

2. Have you written the dictation?

3. She has lost her key somewhere.

4. Has he taken your book?

5. Sorry, I have just made two serious mistakes.

6. Mike is the winner! He has swum 3 km the first.

7. They have already met me today.

8. Has she read the story yet?

9. He has slept since 4 pm. = He has been sleeping since 4 pm - если учили Pres. Perfect Continuous

10. I have just seen her in the corridor.

Объяснение: