题目选项分析

The ivory-billed woodpecker, once the largest woodpecker in North America at a striking 20 inches tall, has moved in and out of the extinct category, with scientists consistently unable to find solid proof that the bird still exists.

The ivory-billed woodpecker, once the largest woodpecker in North America at a striking 20 inches tall, has moved in and out of the extinct category, with scientists consistently unable to find solid proof for the bird's continued existence.