1. (2020高三上·浙江期末) 有如下 VB 程序段：

Dim a(1 To 5)  As Integer

a(1) = 1

For i = 2 To 5

    a(i) = Int(Rnd * 9) +1

    If a(i) Mod 2 = 1 Then

        a(i) = a(i) + a(i - 1)

    ElseIf a(i) mod 2 = 0 Then

        a(i) = a(i) / 2

    End If

Next i

执行程序后，a 数组各元素不可能是（   ）