保险公估公司投保职业责任保险的，应当确保该保险持续有效。
参考答案：对
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
什么是调味油？
