单词	what for?
释义	what for? 为什么？
随便看	convectional drying convectional efficiency convectional flow drying convectional heat transfer coefficient convectional high-speed mixer convectional instability convectional mixing convectional multivibrator convectional power plant convectional precipitation convectional rain convectional reliability convectional signals convectional stability convectional stage tube convectional storm convectional unstable convection and diffusion convection baffle convection bank convection barrier convection-based convection boiler convection boiling convection boundary condition