不知道你说的"小组发表"是不是Group presentation(小组汇报、小组演示)?另外,和教授谈话应注意基本的会话礼仪,建议增加礼貌用语.以下翻译只是针对你提供的内容：
1、Professor xx,I come here today to talk about our group presentation.(建议增加内容) There are two of us in Group 8.But,unfortunately,my partner couldn't make it this time (原因?) So,I was wondering if it would be OK if I joined another group?
2、(Fortunately,) Group 10 have agreed to take me in.So I will be preparing (the presentation) with them.