3 sentences

1. 这些只是空洞的话语。

   zhè​xiē zhǐ​shì kōng​dòng de huà​yǔ.

   These are only empty words.

   Source: CCMatrix

2. 她的音乐很空洞。

   tā de yīn​yuè hěn kōng​dòng.

   Her music is very hollow.

   Source: OpenSubtitles

3. 为什么臭氧空洞只发生在南极，而不是其他地方？

   wèi​shén​me chòu​yǎng​kōng​dòng zhǐ fā​shēng zài nán​jí, ér bù​shì qí​tā dì​fang?

   Why does the ozone hole only happen in Antarctica and not elsewhere?

   Source: CCMatrix