unconvincing

gave an unconvincing excuse.

给出一牵强的

a slightly bizarre and unconvincing fusion of musical forces.

微奇特而并不动人的不同音乐融合。

she managed a brave but unconvincing smile.

她勉强笑了笑，很是勇敢，但让人难以相信是真心笑。

she felt the lie was unconvincing, but he seemed to take it at face value .

她觉得这谎言不信，但他似乎是怎么说怎么信。