useless

adj. /ˈjuːsləs/ B1

无用的；无效的

Not serving any purpose or producing no good result.

仙境例句

Shouting at the arm in the window was useless; it only waved back at them.

对着窗口的手臂大喊大叫毫无用处，它只是朝他们挥了挥。