问题
选择题
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
答案：C
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。