corals having calcareous skeletons aggregations of which form reefs and islands
例句
But in order to do this, he must have been thoroughly familiar with the enormous madrepore of the sewer in all its ramifications and in all its openings. 但是，要这样走，就必须彻底清楚这个巨大珊瑚形阴渠的所有分岔和直管。
