3 sentences

1. 十年时间一晃就过去了。

   shí nián shí​jiān yī​huǎng jiù guò​qù le.

   Ten years passed in a flash.

   Source: Dong Chinese Dictionary

2. 一晃二十年过去了。

   yī​huǎng èr​shí nián guò​qù le.

   Twenty years have passed in a flash.

   Source: OpenSubtitles

3. 人影在窗前一晃就不见了。

   rén​yǐng zài chuāng qián yī​huǎng jiù bù jiàn le.

   A figure flashed by the window and disappeared.

   Source: Dong Chinese Dictionary