I am sorry to say I can't go to BeiJing tour with you next weekend.Because I have a lot of homework this weekend.(隨便寫的突發事件）How about going there the week after next(讓步說下下周去怎麽樣）If not. I wish you have a wonderful trip (如果妳下周要去，我祝妳有壹次美好的旅行）
your friend
IlHua