using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"^[a-zA-Z][a-zA-Z=0-9;]*";
string input = @"3. 宿舍开水一壶价格已达到1元以上，%给学生用水造成很大负担。
4. 空调租赁机制不合理问题，%租赁只能以年为单位，但学生一般只在夏季使用，多出费用很多
5. 厕所洗手液没有%及时更换
matlab=123;%this is a matlab test function
Matlab=123;%this is a matlab test function";
RegexOptions options = RegexOptions.Multiline;
foreach (Match m in Regex.Matches(input, pattern, options))
{
Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index);
}
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx