1. ADJ If you are helpless, you do not have the strength or power to do anything useful or to control or protect yourself. 無能為力的

Parents often feel helpless, knowing that all the hugs in the world won't stop the tears. 家長們常常感到無能為力，知道世上所有的擁抱也不能止住眼淚。

2. helplesslyADV 無能為力地

Their son watched helplessly as they vanished beneath the waves. 他們的兒子無能為力地看著他們消失在海浪之下。