1)air corridor,空中走廊2)border air corridor,边境空中走廊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.