若序列中关键字相同的记录在排序前后的相对次序不变，则称该排序算法是______的。
参考答案：稳定
—All the villagers _____the fight against the big flood, _____young and old, men and women.
— It’s really very brave of them to do so.
A．joined; including
B．joined in; included
C．joined in; including
D．joined; included
如何检查调节阀是否失灵？
