预先beforehand

• 事前通知

  notify in advance

• 事前检查

  check in advance

• 事前请示

  ask for instructions in advance

• 事前准备好

  prepare in advance

• 应事前取得许可

  should get permission in advance

• 事前大家都以为没有什么困难。

  Beforehand everybody thought it would be simple.

• 这件事我事前不知道。

  I did not know about this beforehand.