lag behind on是什么意思？

• 分配英文
• various
• theatre
• 呼吁英语
• brat
• modernize
• 纪念品英语
• algiers
• tomato
• client
• aspect
• searches
• passage
• 缺陷英文
• begins
• ticket
• conflict
• 权限英文
• bothering
• fiercely
• 局外人英文
• prompt
• 导师英文
• volume
• monitor
• bombarded
• general
• vehicle
• 抛弃英文
• explore

• searches
• toxicity
• disappointed
• sweater
• BARRIE
• lycopene
• 实施英文
• rice
• 解决方案英文
• intermission
• 来源英语
• scared
• repeat
• erased
• maths
• 造型的英文
• fake
• 确认英文
• saturday
• droplets
• tourist
• default
• committing
• passage
• pear
• organizations
• giraffe
• silver
• firmness
• peeping

• make mistakes
• be afraid to
• take notes
• be terrified of
• go to sleep
• head teacher
• not any more
• get in the way
• not in the slightest
• hair band
• Oxford University
• Yellow River
• on display
• be bad for
• stay away from
• be in agreement
• barbecue meat
• tag question
• Niagara Falls
• touristy
• Eiffel Tower
• Notre Dame Cathedral
• Ace Travel
• provide with
• as soon as possible
• sportspeople