效用

háo wú xiào yòng

毫无效用

avail to nothing

zēng qiáng xiào yòng

增强效用

enlarge the usefulness

zhè yī fǎ guī yǐ shī qù xiào yòng

这一法规已失去效用。

This legislation has outlived its usefulness.

tā hěn xiāng xìn wéi shēng sù piàn de xiào yòng

他很相信维生素片的效用。

He swears by vitamin pills.