337p日本欧洲大胆_欧美毛片十八禁电影_午夜老司机在线观看_精品导航综合_日本黄色网址免费_丰满少妇高潮一区二区_国产精品天干天干_调教大乳女警察奶水直流_成人區人妻精品一區二區不卡視頻_四虎在线视频免费播放观看网站

The flaw detector test usually emits ultrasound on the object to be measured (such as industrial materials, human body), and then uses its reflection, Doppler effect, transmission, etc. to obtain information inside the measured object and process it to form an image nondestructively.