51.依 UCP600 規定及 ISBP745 之實務補充,運送單據及保險單據均須簽署,但即使信用狀未敘明,下列何種單據依其 性質毋須簽署?(A)匯票(draft)(B)商業發票(commercial invoice)(C)證明書(Certificate)(D)聲明書(Declaration)