In this part of the cave, they could hear an insistent booming sound which they found was caused by a small waterspout shooting down into a pool from the roof of the cave.
在這兒,他們可以聽(tīng)見(jiàn)一種連續(xù)不斷的轟鳴聲。后來(lái)他們發(fā)現(xiàn)這是由山洞頂部的一個(gè)小孔里噴出的水柱跌落到水潭中發(fā)出的聲音。