电话里接受或拒绝邀请
接受会议安排， 例如：
Sure, no problem. Shall we say Thursday at ten?
I'm afraid I have another appointment then.
谈话结束前再次确认时间，例如：
Right, so we'll meet Friday at ten, then, at your office.
通过邮件接受或拒绝邀请
不管您对此会议拒绝还是接受，都应在开头表示谢意，例如：
Thank you for the email.
如果拒绝参加一定要讲明理由，最好给一个折中的做法，例如：
Thank for the invitation, but I'm afraid I won't be in on Friday. However my colleague Li will stand in for me.