请教og 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

(D) doubling to twelve the number of satellites now konwn as orbiting

正确答案是B，为什么不能用D中的as doing而用一个to do呢？

谢谢

这个be known as只能后接 n. 不能加doing

be known to do是对的。

楼主，我也正想头号这个问题呢，和你的疑问一模一样，所以，我也谢谢2楼的朋友