Ответ:
1. Have you written...
Yes, I have. I wrote to him last week.
2. Have your parents bought...
Yes, they have. They bought one last month.
3. Has Ellen worn?
...has...,
...worn...
4. Have you found...
...have...
.,...found...
5. Have the children gone..
...have..
..went...
6. Has Mr. Stewart seen...
has
saw
7. Has the president spoken...
has
spoke
8. Has your soccer team lost...
have
lost
9. Has Sam taken...
has
took
10. Have you met...
have
met