1. The sudden storm was an unexpected event that caught everyone by surprise.
这场突然的暴风雨是一个出乎意料的事件，让每个人都感到惊讶。

2. She received an unexpected gift from a secret admirer.
她收到了一个意外的礼物，来自一个暗恋者。

3. The unexpected arrival of her long-lost sister brought tears of joy to her eyes.
失散已久的姐姐突然出现，让她欣喜若狂，眼泪夺眶而出。