在冬天看到这些鸟是非常罕见的。

It's very ___rare to see these birds in winter.

这是一种只在偏远地区发现的罕见植物物种。

This is a ___rare species of plant found only in remote areas.

热带森林里有许多罕见的鸟。

There are many ___rare birds in the tropical forest.