第1个回答 2008-07-18
Thanks for your hard work. [口语化]
Thanks for your great effort.[正式化,邮件里边这么写不错]
第2个回答 2008-07-18
it's hard on you
辛苦你了
谁说英语没这样说 ?
第3个回答 2008-07-18
Thank you for your hard working. / Thank you for your great effort.
第4个回答 2008-07-18
I'm sorry to trouble you so much`