双胎妊娠并发症错误的是()

A．巨大儿

B．贫血

C．妊高征

D．羊水过多

E．早产

Fire hose couplings（）.

A.are made of bronze，brass，or soft alloy metals

B.should be painted red in order to identify hose lengths

C.are specially hardened to prevent crushing

D.should be greased frequently