n.洞；空穴；腔；蛀洞
I have a toothache because there is a cavity in one of my teeth. 我牙疼，因为我的一颗牙齿上有个洞。
He jammed the material in until the cavity was full. 他用力把材料塞进去，直到空穴完全填满。
The peritoneal cavity is a closed sac. 腹膜腔是一个封闭的囊腔。
The tumor growing in the enteric cavity blocked excretion of food. 肿瘤在肠腔里生长阻碍了食物排泄。
The dentist carefully located the filling in the cavity. 牙医小心地把填塞的东西放入牙洞里。
双凹面
