我当时年轻得多，而且非常天真。

I was much younger then, and very ___naive.

这听起来可能有点理想主义和天真，但我认为这种沟通概念会让世界变得更美好。

It might sound a bit idealistic and ___naive, but I think this concept of communication will make the world a better place.

她太天真了，这么容易就相信陌生人。

She was ___naive to trust strangers so easily.