样线；线状样条

in-line filter

toe the line

geographic vertical【测】;plumb line【测】;vertical line【测】

fluid compression for conveyance in pipe-line systems

manifolding apparatus with means for line selection

isotope-separator-on-line (ISOL)

constant temperature line【热】;isotherm【气象】;isothermal【气象】 物

section insulator trolley line