private circuit...[继续阅读]

    two-way speaker system...[继续阅读]

    unbuilding...[继续阅读]

    mask microphone...[继续阅读]

    near field zone...[继续阅读]

    Doppler effect...[继续阅读]

    tetraphonic recording arrangement...[继续阅读]

    tape base width...[继续阅读]

    piezoelectric microphone...[继续阅读]

    United Nations Information Service;UNIS...[继续阅读]