[求助]GWD29-26 请牛人解答一下吧！

In his experiments with gravity, Isaac Newton showed how the motion of each planet in the solar system results from the combined gravitational pull of the Sun and of all the other planets, each contributing according to their mass and distance from the others.

A.      of all the other planets, each contributing according to their

B.       of all the other planets, with each of them contributing according to their

C.      all the other planets, each of which contributing according to its

D.      all the other planets, each contributing according to its

E.       all the other planets, each of which contribute according to their

答案是D  我选定是C  为什么没有of which 呢？不是指代之前的sun and planets 吗？

请指点～～～

晕 不好意思～

谢谢楼上的哈

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