帮我看一下这两句有没有语法错误,

问题描述:

帮我看一下这两句有没有语法错误,
I graduated from Peking University with a degree in Science and I have passed CET-6 with a mark over 560.
Thank you for your prompt attention to this matter and I will be looking forward to your reply.
哈哈,不是北大毕业的,是作文上的要求。

第一句and前后要在时态结构等上保持一致,所以,不能前面是过去时态后面是完成时态.
我认为应该将have passed 改为passed.或者将一句话改为两句,最好用过去完成时态I graduated from Peking University with a degree in Science.I had passed CET-6 with a mark over 560.