I have been living in the town for nearly thirty years but seldom as lonely as I do now.A

问题补充：

I have been living in the town for nearly thirty years, but seldom as lonely as I do now.

A. have I felt

B. I had felt

C. I have felt

D. had I felt.

答案：

(答案→)A. have I felt

B. I had felt

C. I have felt

D. had I felt.

解析：否定意义的词开头句子采用部分倒装，又根据语境have been living“一直住”可知是在描述过去的动作对现在的影响所以要选A。