单项选择题
A.in duplicate;in quadruplicate;in triplicate B.in quadruplicate;in triplicate;in duplicate C.in triplicate;in duplicate;in quadruplicate D.in duplicate;in triplicate;in quadruplicate
A.Certificate of empty tank;Certificate of fumigation B.Certificate of fumigation;Certificate of cleanliness C.Certificate of empty tank;Certificate of cleanliness D.Certificate of cleanliness;Certificate of empty tank