Under the regulations for cargo vessels，which statement is TRUE concerning fireman’s outfits?（）

A.If a vessel carries two outfits，they may be stored in the same location

B.Each fireman's outfit shall contain a flame safety lamp of an approved type

C.Each fireman's outfit shall contain a fresh-air breathing apparatus

D.All of the above

目前临床上应用的生物瓣膜，其主要缺陷是（）

A.组织相容性差

B.耐久性差

C.需终生抗凝

D.易并发感染

E.血栓栓塞率高