發送短信 : Penetrability of Lightweight Aggregate Concrete

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