string s="abcdeabcdeabcde";
string[] sArray=s.Split('c');
foreach(string i in sArray)
Console.WriteLine(i.ToString());

string s="abcdeabcdeabcde"
string[] sArray1=s.Split(new char[3]{'c','d','e'});
foreach(string i in sArray1)
Console.WriteLine(i.ToString());

string content="agcsmallmacsmallgggsmallytx";
string[]resultString=Regex.Split(content,"small",RegexOptions.IgnoreCase)
foreach(string i in resultString)
Console.WriteLine(i.ToString());