Исправь ошибку:
1.How many time have you been to Great Britain?
2.He hasn't already done his homework.
3.We have climbed this hill twice times.
4.They have cooked this soup yet.
5.Have your friend been to Cuba twice?
6.Have Greg tasted your pancakes yet?

Вроде должно получиться вот так.

1.How many time(s) have you been to Great Britain?  

2.He hasn't (yet) done his homework.  

3.We have climbed this hill (two) times.  

4.They have cooked this soup (already).  

5.(Has) your friend been to Cuba twice?  

6. (Has) Greg tasted your pancakes yet?