蒸汽管道的节流损失在数量和质量上是如何体现的？
Under the Carriage of Goods by Sea Act of 1936，a vessel will be liable for damage to a cargo when the damage arises from（）. ["Unseaworthiness when sailing","Insufficient packing","Quarantine delays","Mismanagement of the vessel"]
用户（）对一个已经注册的文件类型更改与其关联的应用程序。 ["A.不可以","B.有时不可以","C.一定不可以","D.可以"]
化学纤维的制造分为哪几个工序？
单相桥式半控整流电路一共有（）只晶闸管。 ["1","2","3","4"]
机组运行时，引起表面式加热器端差增加的原因有哪些？
