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.
(A) which doubles to twelve the number of satellites now known as orbiting
(B) doubling to twelve the number of satellites now known to orbit
(C) which doubles to twelve the number of satellites now known in orbit around
(D) doubling to twelve the number of satellites now known as orbiting
(E) which doubles to twelve the number of satellites now known that orbit
The pronoun which should be used to refer to a previously mentioned noun, not to the idea expressed in an entire clause. In A, C, and E, which seems to refer to a vague concept involving the detection of moons, but there is no specific noun, such as detection, to which it can refer. Also in E, the use of the phrasing the number... now known that orbit is ungrammatical and unclear. B and D use the correct participial form, doubling, to modify the preceding clause, but D, like A, uses known as orbiting rather than known to orbit, a phrase that is more idiomatic in context. B, therefore, is the best answer.
我有好多問題, 尤其是 OG 解飾看不懂
1. 解釋說 which 應代一個名詞不是代一個句子中觀念, 是說它不能代整個句子嗎 ? 還是是說只是不能代抽象的概念 ?
2. answer A, C, E 中, 他說 which 指代不清楚, 那為啥answer B and D 中的 doubling 會修釋整個句子 ??? 怎麼判斷呢 ??? 而且我記的 莫北北說依句意, which 是修釋 moons 那 doubling 應該也修飾 moons 呀

3. 就句子的結構說, 為甚麼 small 及 previously 中間加逗號呢 ? isn't it "six small, previously unseen moons" 是一個 adj + N 的結構. 有人說 "previously unseen moons circling Uranus" 是插入句 :o ???


