1. Cavities in teeth are caused by decay. 牙齿上的空洞是由龋蚀造成的。
2. Large quantities of water may also be stored in limestones when joints and cracks have been enlarged to form cavities. 当接缝和裂缝扩大形成空洞时,大量的水也会被储存在石灰岩中。
3. The ventral cavity includes the thoracic and abdominopelvic cavities and their subdivisions. 腹侧腔包括胸腔和盆腹腔及其细分。
4. These two compartments are synovial cavities, which consists of an upper and a lower synovial cavity. 这两个隔室是滑膜腔,由上、下滑膜腔组成。