發送短信

數:

提供者:

CAPTCHA:

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

Please enter what you see:

發送短信 : Leapfrogging of vortex rings