那只小狗没有被拴住，在院子里自由奔跑。

The little dog was ___unbound and ran freely in the yard.

他的想象力不受任何限制，创造出许多独特的作品。

His imagination is ___unbound, creating many unique works.

这些未结合的离子在水中自由移动。

The ___unbound ions move freely in the water.