Polycyclization
聚环作用
🗣️ 情景例句
I don't know.
我也说不上来。
I can't handle this alone.
我无法单独处理这事。
The deepest holes of all are made for oil, and they go down to as much as 25,000 feet.
在所有洞穴中，为寻找石油所钻的洞是最深的，这些洞可深达25，000英尺。