单项选择题
A.Ns Fc St B.St Fs Cu C.Fn St Fs D.Fs Ns Fn
A.Ns Sc As St B.Sc As Cs Fs C.Ci Cs As Ns D.Fs Ns As St
A.Cu TCu Cb Fc B.TCu Fc Cc Sc C.Cb Sc Ac Cu D.Fc Cu Cb Cc