恐怖分子将他劫持为人质长达18个月。

The terrorists ___held him hostage for 18 months.

我曾被囚禁在一个狭小的阁楼房间里。

I was ___held prisoner in a tiny attic room.

世界各地的动物被当作囚犯一样关在动物园里。

All around the world animals are ___held as prisoners in zoos.