23. Составьте текст
писем-приглашений и ответов на них из следующих фраз:

1)
...I/ happy to accept/
invitation/ I/ look forward/ to participate/ the exhibition

2) ./response/ your invitation/ conference/ I/
submit/ you/ materials/ your consideration and comment/ your earliest response/
be appreciated

3) ./ very much regret/ I/ cannot accept/ the
invitation/ attend the talks/ next month/ since/ it/ come/ the middle of the
academic semester/ and/ I/ have lectures/ to present

4) ./I/ regret/ I cannot accept/ your kind invitation/
hope/ I/ be able/ visit you some time/ the future