Измените предложения по образцу.I know that he has gone to London.I

Измените предложения по образцу.
I know that he has gone to London.
I knew that he had gone to London .
1)I know that they have forgotten everything.
2)I think that he will return the book.
3)I am sure that she has lost the key.
4)I think they will have lunch at 12 o clock.
5)I think he has had breakfast .
6)I think they have had lunch.
7)I know he has had five tests.
8)I think she has had a test .
9)I think she has had a test .
10) I am sure the has had a lot of things to do.