Excerpt Seven Many thanks for your letter of 25th October 2004, inviting me to attend and chair a session of the forthcoming Second International Conference on Knowledge Economy and Development of Science and Technology to be held in Tokyo, Japan, from August 24 to 25, 2005. Much to my regret, I shall not be able to honour the invition because I have been suffering from ill health this summer. I'm firmly advised that it would be unwise to undertake any distant travel in the near future. I feel very soory to miss the opportunity of meeting you and many of other colleagues in the field of knowledge economy. I wish the conference a complete success.7. It is excerpted from __________. A: a thank-you letter B: an invitation letter C: a letter of rejecting the paper D: a declination letter