1. I am not acquainted with him, so I cannot vouch for his character.
我不熟悉他，所以无法为他的品质作保证。

2. She is well acquainted with the local customs and traditions.
她对当地的风俗习惯非常熟悉。

3. We became acquainted during our time studying abroad.
我们在国外留学期间结识。