问题补充:
The old couple have married for 40 years and never once with each other.
A. they had quarreled
B. they have quarreled
C. have they quarreled
D. had they quarreled
答案:
A. they had quarreled
B. they have quarreled
(答案→)C. have they quarreled
D. had they quarreled
解析:never是否定词,以否定词开头的句子要部分倒装。