The possibility that mass extinctions may recur periodically has given rise to such hypotheses as that of a companion star with a long-period orbit deflecting other bodies from their normal orbits, making some of them fall to Earth as meteors and causing widespread devastation upon impact.

(1) “as that of a companion star with a long-period orbit deflecting other bodies from their normal orbits”是as的什么用法？这是一个独立主格结构吗？that在这里指代什么？

(2)“making some of them fall to Earth as meteors and causing widespread devastation upon impact”是做前面哪个部分的结果状语？它是谁的结果？在这句中them指代什么？

【翻译】周期性发生大规模物种灭绝的可能性导致了这样的假说（理论），如一个在长周期轨道运行的伴星使其他天体从正常轨道偏离，结果使得其中的一些像流星那样落在地球上，在冲击后造成广泛的破坏。

【分析】

(1) such...as...结构表示列举，as 意为“诸如此类的；例如”，that是代词，指代前面hypotheses这个词的单数。又如：such books as this one = books such as this one

with a long-period orbit deflecting other bodies from their normal orbits是分词独立主格结构，作定语修饰a companion star。

(2)“making some of them fall to Earth as meteors and causing widespread devastation upon impact”是句子谓语动词has given rise的结果状语。

them指other bodies（其他天体）。