介于

jiè yú ài qíng yǔ yǒu qíng zhī jiān

介于爱情与友情之间

lie between love and friendship

jiè yú shēng yǔ sǐ zhī jiān

介于生与死之间

lie between life and death

jǐng chá zhèng zài xún zhǎo yī míng nián líng jiè yú èr shí zhì èr shí wǔ suì zhī jiān de nán zǐ

警察正在寻找一名年龄介于二十至二十五岁之间的男子。

Police are looking for a man aged between 20 and 25.