4 sentences

1. 你的手指似乎在两个位置之间来回移动。

   nǐ de shǒu​zhǐ sì​hū zài liǎng ge wèi​zhi zhī​jiān lái​huí yí​dòng.

   Your finger seems to jump back and forth between two positions.

   Source: UM-Corpus: News

2. 我们在公园里来来回回地走了2小时。

   wǒ​men zài gōng​yuán li lái​lái​huí​huí de zǒu le2 xiǎo​shí.

   We walked back and forth in the park for two hours.

   Source: UM-Corpus: Spoken

3. 我们来来回回聊了几分钟，她则继续看似忙碌。

   wǒ​men lái​lái​huí​huí liáo le jǐ fēn​zhōng, tā zé jì​xù kàn​sì máng​lù.

   We chatted back and forth for a few minutes as she continued to look busy.

   Source: CCMatrix

4. 给他一张来回票吧。

   gěi tā yī zhāng lái​huí​piào ba.

   Give him a round-trip ticket.

   Source: OpenSubtitles