单项选择题
A.head(tail(taiI(L))) B.tail(head(head(L))) C.head(tail(head(L))) D.tail(tail(head(L)))
A.A B.B C.C D.D
A.41, 52, 54 B.41, 76, 54 C.41, 76, 52, 54 D.41, 30, 76, 54