string test = "测试测试回复后的文本框中填写分数,然后输入自己士大夫奥斯丁安抚奥斯丁";
int ii = test.IndexOf("分数");
int iBegin = (ii-10)<0?0:ii-10;
int iLength = ((ii+12)<test.Length)?22:(test.Length-iBegin);
string myStr = "..." + test.Substring(iBegin,iLength) + "...";
Response.Write(myStr);