4 sentences

1. 我还没有系上安全带呢。

   wǒ hái méi​yǒu jì shang ān​quán​dài ne.

   I haven't fastened my seat belt yet.

   Source: OpenSubtitles

2. 请回到座位并系上安全带。

   qǐng huí dào zuò​wèi bìng jì shang ān​quán​dài.

   Please return to your seats and fasten your seat belts.

   Source: OpenSubtitles

3. 他把绳索系在自己的腰上。

   tā bǎ shéng​suǒ jì zài zì​jǐ de yāo shang.

   He tied the rope around his waist.

   Source: AI Challenger 2017

4. 如果你有一把椅子，把包的带子系在椅子上。

   rú​guǒ nǐ yǒu yī​bǎ yǐ​zi, bǎ bāo de dài​zi jì zài yǐ​zi shang.

   If you have a chair, tie the strap of your bag to the chair.

   Source: CCMatrix