n.腔,洞,蛀牙,龋洞
Put stuffing into the cavity and truss the bird.
把填料放到腔内,把鸟的腿和翅膀扎紧。
There's a cavity in the boy's tooth.
这个男孩的牙上有一个洞.
The embryo lives in the amniotic cavity.
胚胎在羊膜腔中发育。