下列说法正确的是( )
s ="ATCGCGCTACTGA"
s1 =" ACGT"
n= Len(s)
i=1:j=1:c=0
Do While i <= n and j <=4
If Mid(s, i, 1)=Mid(s1, j,1) Then
j=j+1
End If
i=i+1
Loop
s= Mid(s, 1, i-1)
执行该程序段后,变量s的值是( )
Dim a(1 To 6) As Integer
For i=1 To 6
a(i)= Int(Rnd * 4)+1
If a(i) Mod 2=0 And i Mod 2=0 Then
a(i)=2 * a(i) - a(i - 1)
End If
s=s+Str(a(i))
Next i
执行该程序段后,变量s的值可能是( )
Dim a(1 To 15) As Integer
'生成数组a, a(1)=24:a(2)= 17:a(3)=21:
a(4)=15:a(5)=14 …代码略
n= Val(Text1. Text)
For i=1 To n-1
For j=(n+1) * n/2 To ① Step-1
If ② Then
t=a(j):a(j)=a(j- 1):a(j- 1)=t
End If
Next j
Next i
'将处理后的数组,以金字塔形显示,代码略
上述程序段中①②处的语句分别为( )