(2013·甘肃兰州名校高三检测)I have been living in the United States for 20 years, but seldom so lonely as now.
A. have I felt
B. I had felt
C. I have felt
D. had I felt
网友回答
A. have I felt
B. I had felt
C. I have felt
D. had I felt
解析：A 考查倒装和时态。句意：我在美国生活了20年，但是很少像现在这样感到如此孤独。否定词seldom置于句首，句子要用部分倒装，再根据前面的“have been living”可知此处应用现在完成时。故选A项。