Ppm.
[医] 兆比率(百万分之几)
🗣️ 情景例句
What about my famous apple pie?
我那着名的苹果派呢
Does the back door have a lock on it?
后门上有锁吗？
Good. Put it on the small table, please.
好，把箱子放在那个小桌子上吧！