Remove lines

Questions
1

List lines;

lock (globals)
{
List allLines;

try
{
allLines = globals.lines;
}
catch
{
allLines = System.IO.File.ReadAllLines(“abc.txt”).ToList();
globals.lines = allLines;
}

lines = allLines.Take(25).ToList();
allLines.RemoveRange(0, 25);
}

// Now use the lines variable
// As you can see below, now globals.lines has 25 elements removed
LOG globals.lines[0]

In this code above, When I change allLines.RemoveRange(0, 25);
to allLines.RemoveRange(23, 25);
The results as same as.
Can I take 25 lines but remove lines 23,24&25

2

I am also trying to figure out how to write a an index range, tried:
0,2
0…2
(0,2)
[0,2]

All are invalid… Can you help?