这个秘密计划至今未被公开。

The secret plan has remained ___unexposed to this day.

这些植物因为没有接触过杀虫剂，所以生长得很健康。

These plants grow healthily because they are ___unexposed to pesticides.

她对现代艺术完全不熟悉，从未参观过美术馆。

She is completely ___unexposed to modern art and has never visited an art gallery.