从句数量偏少,且文中有几处句子错误;文中高级词汇不足;过渡词和衔接词使用的比较不错。
John, Firstly I thank a lot for your invitation of the night dinner.But I has to say sorry to you that I can't take part in your dinner. Because I must prepare for an importment exam which I will attend next day.It is very pity for me not to share good time with you.Only one thing I can do is that I hope you have a happy night.Apart from this, I also wish we can make an another appointment of the dinner if you are convenient.