Polyphosphates
(polyphosphate 的复数) 多磷酸盐
🗣️ 情景例句
They'll be here any minute.
他们马上就到了。
Opportunity only knocks once.
机不可失，时不再来。
The further off this solid obstruction, the longer time will elapse for the return of the echo.
固体障碍物越远。回声返回所用时间就越长。