过霖面

beam of variable cross section cross section canonical cross section chamber cross section rectangular cross section beam differential cross section effective cross section concave cross section earthwork cross section inelastic cross section interaction cross section Compton cross section cross section of array reduction of cross section cross-section of load cross section of scattering cross-section of array cross section of stream shape of cross section contraction of cross section cross-section of conductor area of cross section cross section of river