[经] clean bill of draft, clean bill of exchange

bù fù dài tiáo jiàn de huì piào ㄅㄨˋ ㄈㄨˋ ㄉㄞˋ ㄊㄧㄠˊ ㄐㄧㄢˋ ㄉㄜ˙ ㄏㄨㄟˋ ㄆㄧㄠˋ