Exercise is as any other to lose unwanted weight.　A. so useful a wayB. as a useful wayC.

问题补充：

Exercise is as any other to lose unwanted weight.

A. so useful a way

B. as a useful way

C. as useful a way

D. such useful way

答案：

A. so useful a way

B. as a useful way

(答案→)C. as useful a way

D. such useful way

解析：本题考查as…as比较结构,另： as，so，too，how +adj.+a+单数可数名词。【译文】锻炼和其他减肥的方法一样好。