老虎现在是一个濒危物种。

Tigers are now an ___endangered species.

许多濒危物种被动物园拯救，这些动物园能够使它们繁殖。

Many ___endangered species have been saved by zoos which have been able to make them reproduce.

濒危海龟受到国际法的保护。

___Endangered sea turtles are protected by international law.