49. The cameras of the Voyager II spacecraft detected six small, previously unseen moons circling Uranus, which doubles to twelve the number of satellites now known as orbiting the distant planet. B.doubling to twelve the number of satellites now known to orbit

有一个不理解的是这里的B选项中的最后的to orbit这个不定式是怎么个用法？！

请教大家，先谢过了！

我来试试：

这句话可以这样读：doubling the number of satellites that are now known to orbit the distant planet to twelve

查know 的用法 （Longman Dictionary)

be known to do sth (example: Smoking is known to increase a person's risk of developing lung cancer.)

know sb/sth as sth

没有know...as doing sth的说法。

比如：I know him as a teacher. (对）可是，I know him as teaching in a school, 就很别扭。