3 sentences

1. 你的后背会感谢你的。

   nǐ de hòu​bèi huì gǎn​xiè nǐ de.

   Your back will thank you.

   Source: CCMatrix

2. 别拿后背对着我。

   bié ná hòu​bèi duì zhe wǒ.

   Don't turn your back on me.

   Source: OpenSubtitles

3. 他从后背口袋里掏出两块狗饼干。

   tā cóng hòu​bèi kǒu​dai li tāo chū liǎng kuài gǒu bǐng​gān.

   He pulled two dog biscuits out of his back pocket.

   Source: CCMatrix