perilous rock的用法和樣例：
例句
- So,from the great cliff's base,jut spokes of rock crossing from bank to bank,intersecting ditches until the pit's hub cuts them off from meeting.
就像這樣從巖石的基礎有危巖通出去而跨越堤岸和壕溝，降到那把它們截斷和集合起來的井。 - To control the unstable rock, a thorough study is needed as to the geological status of the road's side slope and the causes of the rock's unstableness.
在治理過程中，需要對公路邊坡的地質情況，危巖的發育成因，做出較為透徹的研究。
