授業のあとで、学生が素朴な疑問を先生にぶつけた。
After class, a student put a simple, naive question to the teacher.
努力すれば必ず報われるというのは、あまりに素朴な考え方だ。
The idea that effort is always rewarded is far too naive a way of thinking.
その理論は素朴に過ぎると、多くの研究者から批判された。
The theory was criticized by many researchers as being too naive.