pertinacious

a. 执拗的,顽固的,顽强的

His style of argument in meetings is not so much aggressive as pertinacious.

他在会议上的辩论态度并非锋芒逼人而是坚持己见.

She is the most vocal and pertinacious of all the critics of the policy.

在所有的政策批评家中，她是陈词最多而且最为固执的。