劍橋詞典an electronic device that gives out a radio signal when it receives a similar signal telling it to （發(fā)射機(jī)）應(yīng)答器，轉(zhuǎn)發(fā)器 Aircraft are required by law to carry transponders, so that they can be identified . 按照法律規(guī)定，飛機(jī)必須攜帶應(yīng)答器以便識(shí)別。 返回 transponder