20. Though it was less attractive, John knew the metal box would be more _______. A. terminal B. durable C. persistent D. ultimateable 能，能够的babble 胡言乱语 gabble 口齿不清，含糊不清dabble 戏水，弄水gobble 狼吞虎咽nibble 小口吞咽，细咬fable 寓言sable 丧服persistent 持久的，固执的，永恒的stubborn 固执的obstinate 顽固的adamant 固执的 eternal 永恒的perpetual 永恒的constant 恒定的，常量permanent 永恒的，永久的pledge 发誓hedge 篱笆ledge 窗台edge 边缘