ineffective

adj. /ˌɪnɪˈfektɪv/ B2

无效果的；不起作用的

Not producing the intended or desired effect.

仙境例句

Shouting at the arm in the window was quite ineffective, so the Rabbit tried ladders.

对着窗口的胳膊大喊毫无用处，于是白兔改用梯子。