Part per billion是什么意思？

• polite
• begins
• 参数英文
• tomato
• searches
• bombarded
• monitor
• 缺陷英文
• ultra
• cloud
• rice
• 局外人英文
• general
• 方案英语
• peeping
• organizations
• various
• autumn
• conflict
• lake
• droplets
• supper
• general
• PAXLOVID怎么读
• default
• profile
• explore
• neck
• juice
• 来源英语

• 分配英文
• 解决方案英文
• text
• intermission
• 确认英文
• firmness
• PEGGING
• mind
• chess翻译
• ticket
• scared
• passage
• prompt
• predict
• BARRIE
• 权限英文
• 流浪者英文
• 造型的英文
• lesson
• panicked
• crayon
• approaches
• maths
• amazing
• banger
• 队长的英文
• saturday
• 呼吁英语
• theatre
• lycopene

• owing to
• part with
• pass away
• pass by
• pass on
• pass out
• pass over
• pass through
• pay back
• peel off
• pen pal
• pencil case
• period of time
• perk up
• phase out
• pick out
• pick up
• play a trick on
• play out
• play up
• point of view
• point out
• poker face
• political science
• pop up
• post office
• pour forth
• primary election
• primary school
• prime minister