问题补充:
The roommates have lived for three years and not 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:该题结合倒装结构、考查动词时时态的用法。根据并列句时态一般保持一致的原则,可以排除选项A、D;根据not这个否定副词放在第二个分句之首可知该句要倒装。因此该题最佳答案为C。