运用年限法估算设备的实体性贬值率时，一般首选（）作为设备的总使用年限。

A.折旧寿命

B.物理寿命

C.技术寿命

D.经济寿命

The fire was finally_____ after the building had _____for two hours.    [      ]

A. put off ; caught fire      

B. put away; been on fire    

C. put out ; been on fire    

D. put out; caught fire