First exam

A little late however, Monday this week was my first Chinese exam. I think that it went well... but won't know until results are published. The only mistake I can remember making I still can't decide if it was an error in the situation. I think that I missed a possessive character but I am not sure it was appropriate. I said 我的女朋友做语言教授工作。 Do I need a possessive between yuyan and jiao shou? If I say that she is a language professor that does not mean that she belongs to that discipline, does it? But as far as these things go I think that if that is my biggest mistake I should be fine, however because I don't know I got anything else wrong, having done some more study is that because I have absolutely no idea and I acutaly got nothing right???