文本正在转换为符号

我正在制作一个adz收集器，所以我从网站上获取广告，然后用html获取标题、价格和描述。最后继续输入数据表，将数据表导出到CSV。但问题是代码中的文本很好，但当它导出到CSV时，它就像：

 · 75% of the Controller’s time will focus on accounting: Their role includes:  o 
 Bookkeeping  o Payroll  o Monthly HST  o Trust accounting; Ensuring compliance with the     Real 
 Estate Council requirements  o Financial Statement Preparation  · 25% Will be       management 
 functions:  o Supervise and assist with conveyancing  o Supervise all the office staff (4 - 
 6)  o Other day to day management functions.   Requirements and Qualifications  Essential 
 Skills   · Experience working with government regulated financial reporting  · Experience 
 working with large numbers of people in a customer service oriented role  ·     Experience with 
 Trust Accounting    Additional Assets ....

到处都是符号，我用来导出的代码如下：

public  void DataTable2CSV(DataTable table, string filename, string seperateChar)
    {
        StreamWriter sr = null;
        try
        {
            sr = new StreamWriter(filename, true);
            string seperator = "";
            StringBuilder builder = new StringBuilder();

                foreach (DataColumn col in table.Columns)
                {
                    builder.Append(seperator).Append(col.ColumnName);
                    seperator = seperateChar;
                }
                sr.WriteLine(builder.ToString());

            foreach (DataRow row in table.Rows)
            {
                seperator = "";
                builder = new StringBuilder();
                foreach (DataColumn col in table.Columns)
                {
                    builder.Append(seperator).Append(row[col.ColumnName]);
                    seperator = seperateChar;
                }
                sr.WriteLine(builder.ToString());
            }
        }
        finally
        {
            if (sr != null)
            {
                sr.Close();
            }
        }
    }