短语词组短語two way break before -make contact 雙曏先斷後郃觸點double -break -make contact 雙閉觸點break -before-make [通信]先開後郃;先斷後郃;[電]先斷後通ratio break -make 斷續比Break -Make Ratio 斷續比;[電]通斷比;繙譯 返回 break-make