The stars,some of them at tremendous speeds,are in motion just as the planets are,yet being so far away from Earth that their apparent positions in the sky do not change enough for their movement to be observed during a single human lifetime.
(A) The stars,some of them at tremendous speeds,are in motion just as the planets are,yet being这是并列句 故yet being错
(B) Like the planets,the stars are in motion,some of them at tremendous speeds,but they are
是正确答案
(C) Although like the planets the stars are in motion,some of them at tremendous speeds,yet
同A
(D) As the planets,the stars are in motion,some of them at tremendous speeds,but they are
语义不对 as是介词 作为 的意思
(E) The stars are in motion like the planets,some of which at tremendous speeds are in motion but中,but后面缺主语和谓语动词
句子主干：,the stars are in motion,but they are so far away that their apparent positions do not change enough for their movement to be observed .
代词明确 指代 the stars