第2行加a
i=1
Open "1.txt" For Input As #1
Do Until EOF(1) = True
Line Input #1, s$
i=i+1
if i=2 then s$=s$+"a"
ss$ = ss$ + s$ + vbCrLf
Loop
Close #1
i=1
Open "1.txt" For Input As #1
Do Until EOF(1) = True
Line Input #1, s$
i=i+1
if i=2 then s$=s$+"a"
ss$ = ss$ + s$ + vbCrLf
Loop
Close #1
Open "1.txt" For Input As #1
Do Until EOF(1) = True
Line Input #1, s$
s$=replace(s$,"a","b")
ss$ = ss$ + s$ + vbCrLf
Loop
Close #1
以上据输出到ss$第3行加2 a
on error resume next
i=1
Open "1.txt" For Input As #1
Do Until EOF(1) = True
Line Input #1, s$
i=i+1
if i=3 then s$ = Left(s$, 2) + "a" + Right(s$, Len(s$) - 3)
ss$ = ss$ + s$ + vbCrLf
Loop
Close #1