1)air relay,空中接力2)in-flight,空中3)air powder,空中粉尘4)Air striking,空中打击5)driving birds in air,空中驱鸟6)vertical sampling,空中采样
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.