这是XDF补充材料中的173题

173. Since the 1930’s aircraft manufacturers have tried to build airplanes with frictionless wings, shaped so smoothly and perfectly that the air passing over them would not become turbulent.

A. wings, shaped so smoothly and perfectly

B. wings, wings so smooth and so perfectly shaped

C. wings that are shaped so smooth and perfect

D. wings, shaped in such a smooth and perfect manner

E. wings, wings having been shaped smoothly and perfectly so

这是XDF补充材料中的173题，答案是B。为什么？怎么能有两个wings呢？拜托各位NN们给予解惑。

避免歧异啊!不加WINGS的话可能理解成airplanes (shaped so smoothly and perfectly that the air passing over them would not become turbulen).这样就不好了.

个人意见,学习中的孩子