OG12 Q18 老题新问 平行结构

18. Plants are more efficient at acquiring carbon than are fungi, in the form of carbon dioxide, and converting it to energy-rich sugars.
A) Plants are more efficient at acquiring carbon than are fungi,
(B) Plants are more efficient at acquiring carbon than fungi,
(C) Plants are more efficient than fungi at acquiring carbon,
(D) Plants, more efficient than fungi at acquiring carbon,
(E) Plants acquire carbon more efficiently than fungi,

这句话的意思是Plants are efficient at acquiring and converting，acquiring和converting平行，但是平行结构不是不可以省略介词的吗？所以应该在converting前加个at吧？

127. Joan of Arc, a young Frenchwoman who claimed to be divinely inspired, turned the tide of English victories in her country by liberating the city of Orléans and she persuaded Charles VII of France to claim his throne
(A) she persuaded Charles VII of France to claim his throne
(B) persuaded Charles VII of France in claiming his throne
(C) persuading that the throne be claimed by Charles VII of France
(D) persuaded Charles VII of France to claim his throne
(E) persuading that Charles VII of France should claim the throne

C和E不对是因为要平行的话应该是Joan of Arc turned the tide by liberating and by persuading，后面的那个介词by不可以省略，那为什么18题的介词就可以省略呢？这两题有什么不同啊？

好晕啊，呼唤NN解答~~~~~