2 sentences

1. 他们买了一张单程票。

   tā​men mǎi le yī zhāng dān​chéng​piào.

   They bought a one-way ticket.

   Source: OpenSubtitles

2. 婚姻是一张单程票。

   hūn​yīn shì yī zhāng dān​chéng​piào.

   Marriage is a one-way ticket.

   Source: CCMatrix