movable frog lever

  • 1Railroad switch — For other uses, see Switch (disambiguation). A right hand railroad switch with point indicator pointing to right …

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  • 2muscle — muscleless, adj. muscly, adj. /mus euhl/, n., v., muscled, muscling, adj. n. 1. a tissue composed of cells or fibers, the contraction of which produces movement in the body. 2. an organ, composed of muscle tissue, that contracts to produce a… …

    Universalium

  • 3sound reception — Introduction       response of an organism s aural mechanism, the ear, to a specific form of energy change, or sound waves. Sound waves can be transmitted through gases, liquids, or solids, but the hearing function of each species is particularly …

    Universalium