这句话时态对吗?

问题描述:

这句话时态对吗?
SinceI was a postgraduate student,I have been interested in scientific research.

Since I was a postgraduate student,I have been interested in scientific research.这句话时态对 但since从句 放前面 恐怕会有歧义所以 最好是 I have been interested in scientific research since I was a pos...