Warning: file_put_contents(/home/www/wwwroot/zidian/69228.com/cache/1661b72090452065fcb691727c67fd37.txt): failed to open stream: No space left on device in /home/www/wwwroot/zidian/69228.com/index.php on line 55 在线观看人与动牲交视频,无尺码精品产品图片,大伊人无码综合天堂Av
According to the principles of infinitesimal calculus,a new method on how to ratiocinate the arbitrary quadrilaterals area was put forward. 利用微積分原理給出任意四邊形麪積公式推証的一種新方法。