Verified answer

1 I have just opened the window.

2 He has cleaned his room today.

3 John and Jack have painted a big picture.

4 She has already eaten her biscuit.

5 Have you written the letter to her?

6 We haven't bought a computer yet.

7 Has your mother called a doctor already?

8 They haven't sent this fax yet.

9 I have helped my father.

10 Has Nick read the book already?