by the air or by air

by the air or by air we are often()by colors,weather or the air temperature will you travel by sea or air?和will do travel by sea or air? 1、Which is_______(interesting),traveling by air or by train? will you travel by sea or by air的意思! you _______go to Beijing by air or by train. (with air /in air /by air ./through air) travelling by air by air造句 Travelling by air.. By air 合适么? by air是什么意思