innocuous

这种植物看起来陌生，但实际上是无害的。

The plant looks unfamiliar but is actually ___innocuous.

他以为这是个无害的玩笑，没想到会伤害别人的感情。

He thought it was an ___innocuous joke, but it ended up hurting someone's feelings.

侦探注意到地毯上一块看似不起眼的污渍，后来这成了关键证据。

The detective noticed an ___innocuous stain on the carpet, which later proved to be the key piece of evidence.