用rep函数，生成向量Z=（1 ,1, 1 ,2 ,2, 2,2）的命令是

A.X<-seq[1:10]

B.X<-seq(1, by = 1, length.out = 1)

C.X<-seq(1, by = 10, length.out = 1)

D.X<-seq(1, by = 1, length.out = 10)

A.Y <- gl(3, 2, 6, labels = c(1, 2,3))

B.Y <- gl(3, 2, 6, labels = (1, 2,3))

C.Y <- gl(3, 2, 6, label = c(1, 2,3))

D.Y <- gl(1, 2, 3, labels = c(1, 2,3))

A.A cfs <- 100 * (rep(couponRate/frequency, n) + c(rep(0, n ),1))

B.B cfs <- 100 * (rep(couponRate/frequency, n-1) + c(rep(0, n - 1),1))

C.C cfs <- 100 * (rep(couponRate/frequency, n) + c(rep(0, n - 1))

D.D cfs <- 100 * (rep(couponRate/frequency, n) + c(rep(0, n - 1),1))

A.向量

B.矩阵

C.数据框

D.其余都可以

A.Y.是

B.N.否