發送短信

數:

提供者:

CAPTCHA:

  _____      ___               __   __    ______  
 |__  //    / _ \\    ____     \ \\/ //  /_   _// 
   / //    / //\ \\  |    \\    \ ` //     | ||   
  / //__  |  ___  || | [] ||     | ||     _| ||   
 /_____|| |_||  |_|| |  __//     |_||    /__//    
 `-----`  `-`   `-`  |_|`-`      `-`'    `--`     
                     `-`

Please enter what you see:

發送短信 : Optimal energy transfer pipe arrangement for acoustic drill string telemetry