1)air castle,空中楼阁2)"Attic in the Air" Investment Theory,“空中楼阁”理论3)in-flight,空中4)air powder,空中粉尘5)Air striking,空中打击6)driving birds in air,空中驱鸟
用法和例句
Developed a high-powder,efficient and practical air powder vacuum cleaner after studing its working principle in order to suck up air powder,the vacuum cleaner is vevy practical.