11.Since conscious patients often died of shock on the operating table, the invention of anesthesia was essential to the development of surgery as the invention of the propeller was to powered fight.
A. the invention of anesthesia was essential to the development of surgery as the invention of the propeller was to powered fight
B. inventing anesthesia was as essential for the development of surgery as the invention of the propeller was for powered fight
C. the invention of anesthesia was as essential in the development of surgery much as the invention of the propeller had been for powered fight
D. the invention of anesthesia was as essential to the development of surgery as the invention of the propeller was to powered fight
E. the invention of anesthesia was essential to the development of surgery, so was the invention of the propeller essential to powered fight
the answer is D
請教這題思路
原本我選A
因為我覺得A is to B as C is to D 很平衡