frost-free period
自由土地
free land【经】
暂无补充释义。
相关词条
free-trade port，free port
free and easy
by-pass check valve (free-wheeled checkvalve)
by-pass check valve (free-wheeled check valve)
boost qi4 and free yang2
six bowels fulfill their purposes when there is free flow
assist yang2 and free the stool