1.解析：a couple of 少数几个
be coupled with 与结合
go in couples 成双成对
hunt in couples 协力
run in couples 协力
coupled with 外加
in a couple of shakes 刹那间
It is not every couple that is a pair 成双未必配对。
2.decades n. 十年, 十
解析：for decades on end 数十年如一日
3.definite adj. 明确的, 一定的
解析：definite behavior 果断的行为
4.deny v. 否认, 拒绝
解析：deny oneself 克己,自制
He denies his wife nothing. 他对妻子言听计从。
5.differentiation n. 区别
解析：来自different