单选题
1.The old couple have been 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
正确答案：C
答案解析：本题考查的是倒装结构的用法。第二分句中因有否定副词never提前，故应用倒装结构；第一分句中的have been married已限定了时态，据此可排除D项。