1 sentence

1. 事实上，萤火虫有两种不同的光信号。

   shì​shí​shang, yíng​huǒ​chóng yǒu liǎng zhǒng bù​tóng de guāng​xìn​hào.

   Fireflies, in fact, have two different light signals.

   Source: OpenSubtitles