2 sentences

1. 你觉得他们是兄妹吗？

   nǐ jué​de tā​men shì xiōng​mèi ma?

   Do you think they're brother and sister?

   Source: OpenSubtitles

2. 我们不知道我们是兄妹。

   wǒ​men bù​zhī​dào wǒ​men shì xiōng​mèi.

   We didn't know we were brother and sister.

   Source: OpenSubtitles