例句：

　　It would be futile to protest.

　　抗議也無用。

　　It would be futile to argue with him.

　　跟他爭(zhēng)辯是徒勞的。

　　There is no point in continuing this futile fight!

　　持續(xù)這場(chǎng)無效的戰(zhàn)斗沒有意義！