public static function show_title()
{
$msg = sprintf("\t\t\t\t%s\t%s(%s) => %s(%s)\t\tquery time: %s", self::$query_date, self::$from_station_name, self::$from_station_code, self::$to_station_name, self::$to_station_code, self::$query_num++);
self::show($msg);
}