Ответ:
1) He said he would do it tomorrow afternoon.
2) Mary says she has already read that book.
3) My mother said that she could not tell me the right time.
4) I asked Alex if he had ever traveled by air before.
5) The visitors were told that the guide would come back in twenty minutes.
6) We didn’t know that you had already watched this movie.
7) He admits that he knows the laws of the country.
8) Julia knew why I hadn't come the previous night to the party.